Second-in-command (2i/c or 2IC) is a title denoting that the holder of the title is the second-highest authority within a certain organisation.

Usage

In the

British Army The British Army is the principal land warfare force of the United Kingdom, a part of the British Armed Forces along with the Royal Navy and the Royal Air Force. , the British Army comprises 79,380 regular full-time personnel, 4,090 Gurkha ...

or Royal Marines, the second-in-command is the deputy commander of a unit, from

battalion A battalion is a military unit, typically consisting of 300 to 1,200 soldiers commanded by a lieutenant colonel, and subdivided into a number of companies (usually each commanded by a major or a captain). In some countries, battalions ...

regiment A regiment is a military unit. Its role and size varies markedly, depending on the country, service and/or a specialisation. In Medieval Europe, the term "regiment" denoted any large body of front-line soldiers, recruited or conscript ...

downwards. This terminology is also used in many other Commonwealth armies and other nations. The equivalent appointment in the

United States Army The United States Army (USA) is the land service branch of the United States Armed Forces. It is one of the eight U.S. uniformed services, and is designated as the Army of the United States in the U.S. Constitution.Article II, section 2, ...

is the executive officer. The second-in-command of a battalion or regiment is usually a major. The second-in-command of a company, squadron, or artillery battery (in which they are called the battery captain) is usually a captain (although

infantry Infantry is a military specialization which engages in ground combat on foot. Infantry generally consists of light infantry, mountain infantry, motorized infantry & mechanized infantry, airborne infantry, air assault infantry, and mar ...

company second-in-commands were usually

lieutenant A lieutenant ( , ; abbreviated Lt., Lt, LT, Lieut and similar) is a commissioned officer rank in the armed forces of many nations. The meaning of lieutenant differs in different militaries (see comparative military ranks), but it is often ...

s until after the

Second World War World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the vast majority of the world's countries—including all of the great powers—forming two opposi ...

), the second-in-command of a

platoon A platoon is a military unit typically composed of two or more squads, sections, or patrols. Platoon organization varies depending on the country and the branch, but a platoon can be composed of 50 people, although specific platoons may rang ...

troop A troop is a military sub-subunit, originally a small formation of cavalry, subordinate to a squadron. In many armies a troop is the equivalent element to the infantry section or platoon. Exceptions are the US Cavalry and the King's Tr ...

is the platoon or troop sergeant, and the second-in-command of a section is usually a lance corporal. In the

Royal Navy The Royal Navy (RN) is the United Kingdom's naval warfare force. Although warships were used by English and Scottish kings from the early medieval period, the first major maritime engagements were fought in the Hundred Years' War against Fr ...

and Commonwealth navies, the second-in-command of a vessel, regardless of rank, is known as the

first lieutenant First lieutenant is a commissioned officer military rank in many armed forces; in some forces, it is an appointment. The rank of lieutenant has different meanings in different military formations, but in most forces it is sub-divided into a ...

or executive officer.

Other uses

In common usage, the term refers to a

deputy Deputy or depute may refer to: * Steward (office) * Khalifa, an Arabic title that can signify "deputy" * Deputy (legislator), a legislator in many countries and regions, including: ** A member of a Chamber of Deputies, for example in Italy, Spain, ...

. Its basic meaning is "someone who relieves a commander".

References

{{reflist Military ranks