Replicator (Stargate)

Over its decade of existence, science fiction TV series ''Stargate SG-1'' developed an extensive and detailed backdrop of diverse characters. Many of the characters are members of alien species discovered while exploring the galaxy through the Stargate, although there are an equal number of characters from offworld human civilizations. While ''Stargate SG-1'', ''Stargate Atlantis'' and ''Stargate Universe'' are separate shows, they take part in the same fictional universe, so no character is internally show-specific.

Main characters

Except for the commanders of the top-secret Stargate Command military base (SGC), all main characters of ''Stargate SG-1'' are members of the SG-1 team, the primary unit of the SGC in the show. SG-1's duties include first contact, reconnaissance and combat, diplomacy, initial archaeological surveying, and technological assessment. The composition of SG-1 changes several times during the series run and varies in several alternative universes.

Jack O'Neill

Jack O'Neill is a USAF colonel (later brigadier general, major general and then lieutenant general) who led the original mission through the Stargate in ''Stargate''. He is played by Kurt Russell in the film, and by former ''MacGyver'' actor Richard Dean Anderson in a regular role in seasons 1–8, and in a recurring role in seasons 9–10, also Michael Welch played young Colonel O'Neill in episode "Fragile Balance". He also appears in ''Stargate: Continuum'', and in seasons 1 and 3 of ''Stargate Atlantis''. Colonel O'Neill is the leader of the SG-1 team in the first seven seasons, and takes charge of Stargate Command after his promotion to brigadier general at the beginning of season 8. He is promoted to major general at the beginning of season 9, and is reassigned to Washington, D.C., then makes sporadic appearances in the final episodes of season one of Stargate Universe.

Daniel Jackson

Dr. Daniel Jackson is a brilliant archaeologist and linguist, specializing in Egyptology, whose unusual theories concerning the origin of the Egyptian Pyramids led to his participation in the original mission through the stargate in ''Stargate''. He is played by James Spader in the film and by Michael Shanks in a regular role in seasons 1–5 and 7–10, with a recurring role in season 6. He also appears in both direct-to-DVD films and in seasons 1 and 5 of ''Stargate Atlantis''. Daniel joins the SG-1 team in search of his kidnapped wife (Sha're), until she dies in season 3. However, he decides to remain a part of SG-1, and does so until his ascension at the end of season 5. Following his decision to retake human form, he rejoins SG-1 at the beginning of season 7.

As stated in season 2's "1969", Daniel speaks 23 languages, including Russian, German, Spanish, and Egyptian. Throughout the run of the series, he becomes Earth's foremost expert on the Ancients, and also learns many alien languages, such as Goa'uld, Ancient, and Unas.

Samantha Carter

Samantha "Sam" Carter is an astrophysicist and USAF captain (later major, lieutenant colonel, colonel, then brigadier general). She is played by Amanda Tapping in a regular role in seasons 1–10, in both direct-to-DVD films and makes an appearance in all seasons of ''Stargate Atlantis''. Captain Carter joins SG-1 under the command of Col. O'Neill in season 1. Following her promotion to major in season 3, she is promoted to lieutenant colonel in early season 8 and assumes command of SG-1. She assists Lt. Col. Cameron Mitchell in seasons 9 and 10. After her appearance in ''Stargate: The Ark of Truth'', she is promoted to a "full bird" colonel and becomes the new commander of the Atlantis expedition in season 4 of ''Stargate Atlantis'' before joining SG-1 again for ''Stargate: Continuum''. She is later made the commander of the USS ''George Hammond'', a ''Daedalus''-class Earth ship named after former SGC commander General Hammond, who died in correlation with the actor who played him, Don S. Davis.

Teal'c

Teal'c is a Jaffa from the planet Chulak. He is played by Christopher Judge in a regular role in seasons 1–10, in both direct-to-DVD films and in season 4 of ''Stargate Atlantis''. Throughout the entire run of Stargate SG-1, the only episode that the character was absent was Season 8's " Prometheus Unbound". Teal'c states that he is 101 years old in season 4's " The Light", and ages an additional 50 years in season 10's " Unending". His catchphrase is "Indeed". Teal'c's most notable feature is a golden tattoo on his forehead, a sign that he once served the Goa'uld Apophis as First Prime, the highest Jaffa rank. His interaction with Bra'tac (Apophis' former First Prime) and his own personal experiences led him to doubt the divinity of the Goa'uld.

Teal'c defects from Apophis in the pilot episode and joins the SG-1 team, believing this to be an opportunity to eventually defeat the Goa'uld and bring freedom to all Jaffa." Children of the Gods" He leaves his wife Drey'auc and his son Rya'c behind on Chulak. After succeeding in killing Apophis in season 5's "Enemies", Teal'c and Bra'tac make first progress in uniting a sizable group of Jaffa resistance warriors in season 5's "The Warrior". Teal'c and Bra'tac lose their symbiotes after a sabotaged rebel Jaffa summit in season 6's " The Changeling", but the Tok'ra drug Tretonin can sustain them and eventually becomes instrumental in liberating Jaffa from physiological reliance on Goa'uld symbiotes,. Teal'c and Bra'tac eventually lead the Jaffa to victory over the Goa'uld in season 8's " Reckoning"/" Threads". Teal'c is chosen as a member of the new Jaffa High Council and supports Bra'tac as an interim leader in season 9's " The Fourth Horseman" before a type of government is solidified.

George S. Hammond

George S. Hammond is a USAF Major General (later Lieutenant General) who commands Stargate Command in the first seven seasons. He is played by Don S. Davis in a regular role in seasons 1–7 and in a recurring role afterwards. He also appears in ''Stargate: Continuum'' and season 1 of ''Stargate Atlantis''. Hammond took over from Major General West, commander of the Stargate Project in the original ''Stargate'' film, and originally intended the Stargate Program to be his last assignment before retirement. In season 2's "1969", General Hammond is shown to have worked at the Cheyenne Mountain complex (the present-day location of Stargate Command) in 1969. Hammond originates from Texas and became a widower when his wife died of cancer.

Hammond briefly retires under duress in season 4's "Chain Reaction", where he spends time with his two grandchildren, Kayla and Tessa. He is promoted to the rank of lieutenant general at the beginning of season 8, being placed in command of the new Homeworld Security command, a department in control of Stargate Command, the ''Prometheus'' project, and the Atlantian Antarctica outpost. Hammond recurs in the season 1 of ''Stargate Atlantis'' and seasons 8 through 10 of ''Stargate SG-1''. Hammond appears in a civilian suit instead of a military uniform in season 9's " The Fourth Horseman", and Carter confirms his retired status in season 10's "The Road Not Taken". In his last appearance in the alternate timeline film '' Stargate: Continuum'', Hammond acts as a military advisor to President Henry Hayes.

Don S. Davis knew Richard Dean Anderson (O'Neill) from Anderson's starring role in ''MacGyver'', in which Davis was a stand-in for Dana Elcar (playing Pete Thornton, MacGyver's boss) before making several guest appearances. Davis died from a heart attack at the age of 65 on June 29, 2008, shortly before the release of ''Continuum'', making this his final on-screen appearance as General Hammond. For his portrayal of Hammond, Don S. Davis was nominated for a 2004 Leo Award in the category "Dramatic Series: Best Supporting Performance by a Male" for the season 7 episode " Heroes, Part 2".

Jonas Quinn

Jonas Quinn is an alien from the planet Langara. He is played by former ''Parker Lewis Can't Lose'' actor Corin Nemec in a regular role in season 6, and in a recurring capacity in seasons 5 and 7. Jonas leaves his home planet Langara the penultimate season 5 episode " Meridian" after witnessing Daniel Jackson's lethal sacrifice and the following gleeful reaction of his planet's leaders. He is a fast learner and fills Daniel's empty spot on SG-1 in season 6. Following Daniel's return at the beginning of season 7, Jonas returns to his planet and last appears in the mid-season 7 episode "Fallout".

Corin Nemec replaced Michael Shanks (Daniel Jackson) during season 6 after Shanks had left the show amid controversy after season 5. The producers based Jonas's motivation to join SG-1 on his momentary reluctance to actively prevent Daniel's death and his feelings of responsibility afterwards. Jonas was slowly integrated into the story in a prolonged transition stage over the first half of season 6. Nemec was open to continue playing Jonas Quinn after season 6, but a new contract was reached with Michael Shanks for Daniel to return in season 7. The role of Jonas was reduced to recurring status in season 7.

Cameron Mitchell

Cameron "Cam" Mitchell is a USAF lieutenant colonel. He is played by former ''Farscape'' actor Ben Browder in a regular role in seasons 9–10 and in both direct-to-DVD films. Mitchell is introduced in "Avalon" as the leader of a squadron of F-302s against the forces of the arch villain Anubis in season 7's "Lost City". Assigned as the new commanding officer of SG-1 at the beginning of season 9, Mitchell struggles to reunite the team's former members under his command. Assisted by Carter (who is of equal rank), he remains in command of SG-1 throughout the series run and both films. He is promoted to the rank of full-bird Colonel in ''Stargate: Continuum''.

Ben Browder joined the cast after Richard Dean Anderson's departure from ''Stargate SG-1'' in 2005. From the beginning, producer Robert C. Cooper wanted Mitchell to be a "super fan" of SG-1 who is openly enthusiastic about exploring the galaxy. Mitchell is often at the center of the action and fight sequences. The producers did not realize the physical resemblance between Browder and Michael Shanks when Browder was cast, and employed make-up and costuming techniques to make the transition easier for the audience. The writers' decision to put Mitchell in command of SG-1 instead of Carter was met with resistance by some critics and audience members. For his portrayal of Cameron Mitchell, Ben Browder was nominated for a Saturn Award in the category "Best Supporting Actor on Television" in 2006.

Hank Landry

Henry "Hank" Landry is a United States Air Force Major General and the commander of Stargate Command from season 9 onwards. He is played by Beau Bridges in a regular role in seasons 9–10, in both direct-to-DVD films, and in the ''Stargate Atlantis'' episodes " The Intruder", "Critical Mass", "No Man's Land", and the two-part episode " The Return" of seasons 2 and 3. General Landry is introduced in ''SG-1'' season 9 premiere, "Avalon", having been hand-picked by Jack O'Neill to succeed him. Landry once served as a pilot in the Vietnam War and met a Vietnamese woman named Kim Lam. They had a child, Carolyn Lam, but Landry became estranged to them and left them due to his involvement in military intelligence. Carolyn Lam grew up to be a doctor and was assigned to Stargate Command as chief medical officer in seasons 9 and 10. Bridges said that "Landry truly loves his work utrespects and appreciates his daughter. He wants a real relationship with her and hopes that will happen some day. At the start of eason 9 you're not sure what their relationship is." The late season 10 episode "Family Ties" brings some conclusion to the Landry-Lam enstrangement, showing a reunification between Landry, Carolyn and Kim Lam in a restaurant.

''TV Zone'''s Steven Eramo described Landry as "fair, intelligent, even-tempered and having a good sense of humour". Bridges thought that "andrylikes to empower his team. He realizes how challenged they are. It's a huge burden to protect their country from the entire galaxy, but he also recognizes that, like himself, they are human beings. ..Sometimes he does that with a bark, and sometimes with a bite, but he also has a sense of humor, this man. And he likes to fool with people." According to Bridges, Landry appreciates Carter's knowledge, and needed some patience with the fast-speaking Daniel Jackson to realize "how important a piece of puzzle" he is. He respects Teal'c as a warrior, and is willing to foster the potential he sees in Vala.

The ''Stargate'' producers approached Beau Bridges, a self-claimed fan of science fiction, directly to play the role of Hank Landry. Although the producers had some ideas for the characters, they collaborated with Bridges to develop the character's backstory before the writing of season 9 began. Bridges wanted the character to be three-dimensional by revealing a layered backstory over the course of the show. Bridges researched famous US generals from George Washington to John P. Jumper to get a feeling for the role. He accumulated quotes by generals that Landry would respect, and gave the list to producer Robert C. Cooper, who in turn used it as free research. Bridges made no deliberate effort to distinguish his character from General O'Neill, believing that the character could stand on his own.

Vala Mal Doran

Vala Mal Doran is a con artist from an unnamed planet and a former human host to the Goa'uld Qetesh. She is played by former ''Farscape'' actress Claudia Black in a regular role in season 10 after having recurred in seasons 8 and 9 of ''SG-1''. Her first appearance in season 8's " Prometheus Unbound" is followed by a recurring role in season 9, where she and Daniel unintentionally set off the new Ori threat. She joins SG-1 after giving birth to the new leader of the Ori at the beginning of season 10, and appears in both direct-to-DVD films.

Vala was created by Damian Kindler and Robert C. Cooper as a one-time character, but because of the on-screen chemistry between Black's Vala and Shanks' character Daniel Jackson, and the character's popularity with the producers and the audience, Claudia Black became a recurring guest star in season 9 and joined the main cast in season 10. For her portrayal of Vala, Claudia Black was nominated for a 2006 Saturn Award in the category "Best Supporting Actress on Television", and won a Constellation Award in the category "Best Female Performance in a 2006 Science Fiction Television" in 2007.

Recurring Stargate Command personnel

The Stargate Command (SGC) is a fictional military base (and real broom closet) at the Cheyenne Mountain complex near Colorado Springs, Colorado. It is the main setting in ''Stargate SG-1'' and occasionally features on ''Stargate Atlantis''. The base extends many levels beneath the ground and is protected from most forms of attack including indirect nuclear detonations, also serving to contain biological, chemical or alien hazards to the outside world by means of a 'lockdown' status. Stargate Command is typically commanded by a General and is staffed by subject matter experts and military support personnel, several elite special operations teams, and several SG teams, including SG-1. The majority of the teams are United States Air Force with some United States Marine Corps, civilians and United States Army, but other nations have SG teams operating from the SGC as well after the events of season 5.

Janet Fraiser

Captain/Major Janet Fraiser, the resident Chief Medical Officer of the SGC (played by Teryl Rothery, seasons 1–7, 9) – She is responsible for maintaining the health of the SG teams, as well as the SGC's support staff and base personnel. On many occasions, she also cares for the health of alien refugees to Earth, including Goa'uld symbiotes. In her first appearance in " The Broca Divide", Dr. Fraiser holds the rank of captain, and is promoted to major in Season 3. In season 1's " Singularity", Fraiser adopts Cassandra, an alien orphan whose people had been exterminated by the Goa'uld System Lord Nirrti. Dr. Fraiser is killed by a staffweapon blast in season 7's " Heroes" during an off-world medical emergency, but she returns in season 9's "Ripple Effect" as a parallel universe version of Dr. Fraiser, in her reality a regular member of SG-1. Before Fraiser returns to her reality, Carter, Jackson and Teal'c are able to give her a final goodbye. Dr. Fraiser is also shown alive in an alternate timeline in the year 2010 in season 4's "2010", but Fraiser and SG-1 alter the timeline to prevent a catastrophe on Earth involving the Aschen race.

Fraiser joined the United States Air Force (USAF) after breaking up with her husband; there she got some training with firearms. Her husband did not want Fraiser to join the US military which is one of the main reasons for their breakup. As a doctor, Fraiser looks for peaceful solutions and is disinclined towards armed solutions. In the episode "Serpent's Song", Fraiser is the only one in Stargate Command (SGC) who is resistant to the idea to give Apophis over to his enemies. She is eventually forced to give up Apophis.

Teryl Rothery was asked by then producer and writer (for ''Stargate'') Jonathan Glassner and Brad Wright if she wanted to play the role as Fraiser. In an interview, Rothery was asked what it was like to play a doctor in ''Stargate SG-1''. Rothery replied, "just being true to the character. And as far as the medical stuff, knowing what to do and what to say." She got a lot of help from the medical advisor on the set.

In the first two seasons, Rothery did not have a contract and was booked on every episode in which she appeared. In season three of ''SG-1'', she finally got a contract deal with the producers. She also commented on her acting life once, "The life of an actor is always very up and down. So sometimes you work a lot, but sometimes ... So if you're on a series like ''Stargate SG-1'' you have that work for seven years. So that's a gift."

After her character's death in season 7, there were various rumours which said she would appear in the upcoming ''Stargate'' film; this never happened. Rothery said it was unlikely since she had not had any contact with the ''Stargate'' producers since her character's death. Rothery has stated many times that she "admires" the character because of her "strength" and "intelligence". Robert C. Cooper, producer for ''Stargate SG-1'', called Rothery about the death of her character. Cooper said, "It is our last year, so we are thinking of killing one of our regulars." Fraiser was killed off in the episode " Heroes" because the producers thought season seven would be the last in the series and felt that a death of the main cast was needed. Rothery also appeared on the ''Women of Sci-Fi calendar'' produced by fellow ''Stargate'' cast Michael Shanks and Christopher Judge.

Walter Harriman

Chief Master Sergeant Walter Harriman (also known as the Chevron Guy among others, portrayed by Gary Jones, seasons 1–10) joined the Stargate Command (SGC) after excelling in navigation and automatic flight control operations during the first Gulf War. General Hammond recruited him as someone with excellent technical ability and a cool head to operate the Stargate under extreme pressure. He specializes in installing, maintaining and repairing bomb navigation, weapons control as well as automatic flight control systems. He is also an expert in radio and navigational equipment, and in maintaining test and precision measurement equipment. He is primarily a Stargate technician, running the dialing computer and other equipment from the Control Room. He also acts as an occasional administrative assistant to the head of Stargate Command, and has manned the flight console on the bridge of the Prometheus. From season 8 to 10, Harriman's role is expanded to advisor to the Head of Command of the SGC.

His name has been a source of confusion for many fans of ''Stargate SG-1''. Originally, he was simply "Technician" or "Sergeant", listed as such in the show credits. At some point, some of the writers gave him the name "Norman Davis", which came with a name tag, but was never used in dialogue. In the episode "2010", Jack O'Neill refers to him as "Walter". Later, in the eighth season of "Stargate SG-1", the character is addressed as "Sergeant Harriman", with "Harriman" actually based on General George Hammond addressing him as "Airman" what was misheard by fans because of Don S. Davis's Texan accent, resulting in the final name of "Walter Harriman". Many fans fondly refer to him as "the Chevron guy" as many of his on-screen appearances, especially earlier on in the show, had him saying "Chevron (insert number here) encoded". On several DVD commentaries after the introduction of the name "Walter", producer-director Peter DeLuise refers to the character as "Walter Norman" and "Walter Norman Davis". The first time he ever says his own name is in the ''Stargate Atlantis'' episode "Home".

As the series continued Harriman got a heavier role in the series. According to Jones, his role was expanded since Richard Dean Anderson wanted him as his personal assistant in the show when his character Jack O'Neill was the leader of the SGC. The ''Stargate'' producer and writer staff called 2005, ''The Year of Walter'' because the staff evolved Harriman's relationship with General Hank Landry. Jones does not have a binding contract with the ''Stargate'' producers.

Charles Kawalsky

Charles Kawalsky portrayed by John Diehl (in the film) and Jay Acovone (in the series), is introduced in the 1994 ''Stargate'' as lieutenant colonel. He is Jack O'Neill's second in command for the first mission through the Stargate to Abydos and returns to Earth afterwards. When the Goa'uld Apophis attacks the SGC in the pilot episode of ''Stargate SG-1'', Kawalsky is re-introduced as a captain and reunites with his former teammates to bring Daniel Jackson back to Earth. Kawalsky is promoted to major and becomes the leader of the newly formed SG-2 team, accompanying SG-1 on their mission to Chulak to rescue Sha're and Skaara. However, before returning to Earth, Kawalsky is invaded by a Goa'uld parasite from a dead Jaffa warrior. In season 1's " The Enemy Within", the symbiote starts to take control of him back on Earth. A surgical removal of the Goa'uld is initially successful, but the symbiote turns out to be a dead husk whose intelligence has already taken over Kawalsky's mind. Kawalsky is eventually killed when Teal'c forces his head through the event horizon and closes the gate, severing most of Kawalsky's skull including the lobes controlled by the symbiote.

Despite the character's death, Kawalsky appears several more times in the series. In season 2's " The Gamekeeper", O'Neill and Teal'c encounter Kawalsky in a virtual reality simulation. In season 3's " Point of View", Kawalsky and Samantha Carter from an alternate reality arrive through the gate seeking help in contacting the Asgard. His last appearance is in season 8's " Moebius", in which Kawalsky returns in an alternate timeline accidentally created when the destruction of their time machine traps SG-1 in the distant past. Kawalsky accompanies O'Neill, Carter and Daniel to Chulak and again meets his end, although here he is merely shot; it is the alternate Daniel Jackson who is infected with the Goa'uld and killed by Teal'c.

Darren Sumner called Kawalsky "one of the 994film's strongest characters". Sumner called the high death numbers of secondary and recurring characters on the show, ''The Kawalsky Effect''. A Kawalsky action figure was created after the release of the 1994 film. He also has a card in the card game, ''Stargate TCG''. In the card game he is listed as a good soldier. While only appearing in six episodes in total, actor Jay Acovone frequently appears at ''Stargate'' conventions.

Sylvester "Sly" Siler

Master Sergeant Sylvester "Sly" Siler, (played by Dan Shea, seasons 1–10) – A sergeant at the SGC and one of its primary technicians and engineers. First appearing in season 1's " Solitudes", he remains a background character throughout the run of ''Stargate SG-1'' and also occasionally appears in Earth-based episodes of ''Stargate Atlantis''. Dan Shea is primarily the stunt co-ordinator for ''Stargate SG-1'', responsible for the budgets and locations of stunts, and the hiring of stunt people before co-ordinating all stunt action. Siler is subsequently shown to be involved in many accidents at the SGC, which is parodied in dialogue and action in several ''SG-1'' episodes such as season 4's "Window of Opportunity", season 7's " Heroes" and the milestone episode "200".

Shea first auditioned for the role as Siler with executive producer Brad Wright and director Martin Wood. Shea commented on his first audition that he tried to be "Funny", thinking he could get the role easier that way. Executive producer Michael Greenberg said that Shea "Blew it", Shea then went for a second audition acting more serious, since according to Greenberg the role was "Serious" and he needed to act that way. Siler also frequently appears in the background of scenes carrying an oversized wrench, which he sometimes hands to director Martin Wood as a gag prop in the series. Siler's first name is never mentioned in dialogue in the series, although his uniform patch and magazines give his first name as "Sly" several times, and his uniform patch in "Entity" reads "Dan". According to producer and writer Peter DeLuise, Siler's name and dialog deliberately contain the letter "S" because Dan Shea lisps.

Shea had previous worked with both Richard Dean Anderson (who portrayed Jack O'Neill) and Greenberg before on the American television series ''MacGyver'' in the 80s and early 90s as Anderson's stand-in in stunt scenes, he continued this role in ''Stargate SG-1''. Anderson's partner Greenberg gave the job as stunt coordinator and stand-in to Shea in ''Stargate SG-1''. The first time Shea was officially double for Anderson was in Toronto when they did a ''MacGyver'' movie; Anderson had broken his foot so Shea was forced to do a stand-in.

Minor characters

* Major Louis Ferretti, (played by French Stewart in the film as Lieutenant Louis Ferretti and Brent Stait in season 1) – A member of the United States Air Force and one of the four survivors of the first expedition through the Stargate in ''Stargate''. Ferretti joins O'Neill's team on another mission to Abydos in " Children of the Gods", and is put in charge of the SG-2 team after the death of Charles Kawalsky in " The Enemy Within". Ferretti makes his last appearance in season 1's " Within the Serpent's Grasp" to follow SG-1 through the Stargate, and is mentioned in season 3's "Shades of Grey" as a possible new leader of SG-1.
* Colonel Robert Makepeace (played by Steve Makaj, seasons 1–3) was a former member of the United States Marine Corps and of Stargate Command (SGC). Originally, Makepeace was the commander of SG-3. His first on-screen appearance is in " The Broca Divide" as ranking officer and team leader of SG-3. He reappears in the two episodes, two-parters in ''Stargate SG-1'' season 2. In the two-parters of season 2, Makepeace leads a rescue mission to save SG-1 (without Teal'c) from the grasp of Hathor in " Into the Fire". In season 3's "Shades of Grey", Makepeace is discovered to be a spy for the rogue N.I.D. group under the command of Colonel Harry Maybourne, who is covertly reverse-engineering stolen alien technologies. Smaller items stolen by the rogue group would be left on a designated world for Makepeace to covertly pick up and pack back to Earth in his gear during routine missions. O'Neill had Makepeace arrested and charged with high treason against the United States and its allies. While it is unknown who immediately replaced Makepeace as the commander of SG-3, eventually this position was assigned to Colonel Reynolds.
* Colonel Albert Reynolds, (played by Eric Breker, seasons 2, 5, 7–10) – Introduced in "Touchstone" as a Major stationed at Area 51 and a member of the National Intelligence Department (NID). In early 2001, He is promoted to lieutenant colonel and was given command of SG-16 on a mission to Velona. By early 2003, Reynolds had received command of SG-3, succeeding Robert Makepeace who was charged for high treason against the United States and its allies. He was also one of the few airman who helped Jack O'Neill defend Stargate Command against the Replicator army that Replicator Carter had sent through the Stargate to attack Earth while she focused on conquering the Milky Way galaxy. Reynolds was the leader of the SGC during Hank Landry's vacation to Jack O'Neill's cabin, Samantha Carter assumed his post until he returned from his mission to P9J-333.
* Doctor Robert Rothman, (played by Jason Schombing, seasons 3–4) – A scientist who prior to joining Stargate Command was Daniel's research assistant. He first appears in season 3's "Forever In A Day" in a Hand device-induced delusion of Daniel Jackson, where he is placed on SG-1. His first non-fantasy appearance is in "Crystal Skull", where Rothman is tasked with researching a crystal skull. Rothman becomes a host to a Goa'uld larva and during a rescue mission on an offworld archaeological dig site in " The First Ones" and is shot dead by Colonel Jack O'Neill.
* Major Michael Griff, (played by Russell Ferrier, season 4) – Was a member of SG-2 as a captain. He accompanied SG-1 in its search to recover SG-11 and Dr. Daniel Jackson on P3X-888; during the course of the mission he was wounded by a staff weapon blast, but recovered. As commander of SG-2, Griff led a search for SG-1 after that team went missing on P3R-118. After braving a glacier that Administrator Calder had insisted SG-1 had set out to investigate, he became convinced that Colonel O'Neill would never have authorized such a mission. At General Hammond's instruction, Griff drew up plans for a covert search and rescue mission, which ultimately proved unnecessary. Later that year, Griff and SG-2 were assigned to "babysit" a team of scientists on M4C-862, a mission he sarcastically described as "non-stop excitement". When O'Neill and Teal'c arrived to relieve him, he was visibly pleased not to be responsible for dealing with the scientists anymore.
* Doctor Bill Lee, (played by Bill Dow, seasons 4, 6–10) – A civilian scientist and engineer who works at Stargate Command and is often called upon to work with alien technology. He first appears in "Prodigy" but does not step in the foreground until "Evolution" where he and Daniel go on a mission to Honduras to locate the Ancients' healing device but are captured and tortured by local terrorists. As seen in " Heroes", Dr. Lee is responsible for creating a staff weapon-resistant armor. He is also a recurring character on ''Stargate Atlantis''. He devises a way to relay a warning to Atlantis in "Critical Mass" and gates to the Pegasus Galaxy from the Midway Station in "Adrift" when Atlantis goes missing. Dr. Lee remains stationed at Midway, training Kavanagh as his replacement, until the midway station is destroyed in " Midway". Dr. Lee is seen in Stargate Universe's pilot "Air" as Dr. Nicholas Rush (Robert Carlyle) uses the Ancient Communication stones (see Ancient technology in Stargate) to trade places with him. In "Twin Destinies," Eli Wallace switches bodies with Lee to present his plan for dialing the Stargate from within a star to Homeworld Command while Lee is presented the plan on ''Destiny''.
* Major Evan Lorne, (played by Kavan Smith, seasons 7 and 10) – A member of SG-11, Lorne first appears in ''Stargate SG-1'' episode " Enemy Mine". Lorne appears as the team leader of the SG-1 unit in an alternate universe in the ''SG-1'' season 10 episode "The Road Not Taken". Lorne reappears as a part of the new personnel sent after the Wraith siege by the ''Daedalus'' in the ''Stargate Atlantis'' episode "Runner". A natural carrier of the Ancient gene, Lorne becomes a major recurring character in ''Stargate Atlantis'', often acting as backup for John Sheppard and his team and seemingly Sheppard's second-in-command. Lorne's final appearance is in "Enemy at the Gate" where he joins Sheppard's team in boarding a hive ship orbiting the Earth in an attempt to destroy it from the inside.
* Doctor Carolyn Lam, (played by Lexa Doig, seasons 9–10) – Stargate Command's chief medical officer in seasons 9 and 10. She first appears in " Avalon Part 2" and is seemingly the first permanent one since the death of Dr. Janet Fraiser in season 7. Prior to joining Stargate Command, Dr. Lam worked with the Centers for Disease Control and Prevention; her specialty is infectious diseases. Dr. Lam has a strained relationship with her father, General Hank Landry. In " The Fourth Horseman", General Landry apologizes for not having been with her when she needed him as a child. Carolyn, her father and her mother Kim Lam, have dinner in the episode "Family Ties". Actress Lexa Doig is the real life spouse of Michael Shanks, who plays Daniel.

Recurring oversight agency characters

The NID is a shadowy intelligence agency that appears throughout the run of ''Stargate SG-1'' and occasionally on ''Stargate Atlantis''. The official mandate of the NID is to provide vital civilian oversight of top secret military operations, but one of their unofficial primary goals is to procure alien technologies. A set of well-resourced illegal cells named the Rogue NID uses unscrupulous methods to achieve the goals of the official NID and is later replaced by The Trust, a shady interplanetary terrorist group. The International Oversight Advisory (IOA) is a civilian oversight committee created after the United States and Russia revealed the existence of the Stargate Program to the other permanent members of the UN Security Council in season 6.

The producers initially wanted to call the NID "NRD" for "No Real Department", but went for "NID" because it sounded better. Although the acronym still stands for nothing in particular, the Stargate SG-1 Roleplaying Game says it stands for National Intelligence Department. When the producers came up with story ideas for the Trust, they found that ''Alias'' had used all the names they could think of. It was not until several weeks after they had decided on the name "Trust" that they found out that ''Alias'' had used that name as well. Faced with the choice to either go with the Trust or with what producer Joseph Mallozzi called "The Former Rogue Elements of the N.I.D. Now Working for Private Interests Bent on Global Domination", they chose the first option. The IOA has also been referred to as the "International Oversight Committee" on the show, until producer Joseph Mallozzi realized during the writing of " The Ties That Bind" that the acronym IOC is already used by the International Olympic Committee. The writers originally wanted to set up an IOA watchdog character on ''SG-1'' and possibly have Richard Woolsey on the base all the time, but season 9 already had so many new characters that the writers did not develop this idea.

Malcolm Barrett

Special agent Malcolm Barrett, (played by Peter Flemming, seasons 5–7, 9–10) – An NID agent introduced in season 5's " Wormhole X-Treme!". His first significant appearance follows in " Smoke & Mirrors", where he helps uncovering a shadow group behind the NID who tried to attribute Senator Kinsey's apparent assassination to O'Neill. After collaborating with SG-1 in season 7's " Heroes, Part 2" and "Resurrection", Barrett expresses a personal romantic interest in Samantha Carter in season 9's "Ex Deus Machina" and season 10's " Uninvited", but she rejects his advances. His last ''SG-1'' appearance is in season 10's "Dominion". Agent Barrett also recurs in ''Stargate Atlantis''. He warns General Landry in that show's season 2 episode "Critical Mass" of the Trust's plan to destroy Atlantis with a bomb, and aids several Expedition team members to track down Rodney McKay's sister Jeannie Miller on Earth in season 4's "Miller's Crossing".

Peter Flemming had a two-line audition for "Wormhole X-Treme" for a " Man in Black" character in a possible recurring role. Every NID character introduced before Agent Barrett "had been very shady, always had an agenda", and Barrett was "the first mainstay in NID who is actually law-abiding .. honest, nda good person".

Harry Maybourne

Colonel Harry Maybourne, (played by Tom McBeath, seasons 1–6, 8) – A USAF Colonel introduced in season 1's "Enigma" as an NID member with ambiguous morals and loyalties. In season 2's "Bane", Maybourne leads an NID attempt to claim Teal'c for study after alien insect infected Teal'c. After further antagonizing SG-1 through rogue NID operations in "Touchstone" and "Shades of Grey", and helping SG-1 in "Foothold