Samothes

The following list of legendary kings of Britain derives predominantly from Geoffrey of Monmouth's circa 1136 work ''Historia Regum Britanniae'' ("the History of the Kings of Britain"). Geoffrey constructed a largely fictional history for the Britons (ancestors of the Welsh, the Cornish and the Bretons), partly based on the work of earlier medieval historians like Gildas, Nennius and Bede, partly from Welsh genealogies and saints' lives, partly from sources now lost and unidentifiable, and partly from his own imagination (see bibliography). Several of his kings are based on genuine historical figures, but appear in unhistorical narratives. A number of Middle Welsh versions of Geoffrey's ''Historia'' exist. All post-date Geoffrey's text, but may give us some insight into any native traditions Geoffrey may have drawn on.

Geoffrey's narrative begins with the exiled Trojan prince Brutus, after whom Britain is supposedly named, a tradition previously recorded in less elaborate form in the 9th century ''Historia Brittonum''. Brutus is a descendant of Aeneas, the legendary Trojan ancestor of the founders of Rome, and his story is evidently related to Roman foundation legends.

The kings before Brutus come from a document purporting to trace the travels of Noah and his offspring in Europe, and once attributed to the Chaldean historian Berossus, but now considered to have been a fabrication by the 15th-century Italian monk Annio da Viterbo, who first published it. Renaissance historians like John Bale and Raphael Holinshed took the list of kings of "Celtica" given by pseudo-Berossus and made them into kings of Britain as well as Gaul. John Milton records these traditions in his ''History of Britain'', although he gives them little credence.

Brutus of Britain (Brutus of Troy)

Historia Brittonum, which is a history of the Celtic Britons written in north Wales in 829–30, claims that the Celtic Britons were descended from Trojans from the ancient city of Troy, who were the first to settle on the island of Britain. It is also claimed in Historia Brittonum, as well as Historia Regum Britanniae by Geoffrey of Monmouth that the first King of the Britons was Brutus of Troy and that the island of Britain was named after him.

Lucius of Britain

Lucius was a legendary 2nd-century King of the Britons traditionally credited with introducing Christianity into Britain. Lucius is first mentioned in a 6th-century version of the ''Liber Pontificalis'', which says that he sent a letter to Pope Eleutherius asking to be made a Christian. The story became widespread after it was repeated in the 8th century by Bede in his ''Ecclesiastical History of the English People'', who added the detail that after Eleutherius granted Lucius' request, the Britons followed their king in conversion and maintained the Christian faith until the Diocletianic Persecution of 303. Later writers expanded the legend, giving accounts of missionary activity under Lucius and attributing to him the foundation of certain churches.

There is no contemporary evidence for a king of this name. In 1904 Adolf von Harnack proposed that there had been a scribal error in Liber Pontificalis with ‘Britanio' being written as an erroneous expansion for ' Britio', a citadel of Edessa, present day Şanlıurfa in Turkey. The name of the King of Edessa contemporaraneous with Pope Eleutherius was Lucius Aelius Aurelius Abgar VIII.

''Des grantz geanz''

''Des grantz geanz'' ("Of the Great Giants"), a 14th-century Anglo-Norman poem, contains a variant story regarding Albion, the oldest recorded name for Britain, and also contains a slightly different list of kings. The poem states that a colony of exiled Greek royals led by a Queen called Albina first founded Britain but before their settlement "no one dwelt there". Albina subsequently gave her name first to Britain, which was later renamed Britain after Brutus. The poem also attempts by euhemerism to rationalise the legends of giants; Albina is thus described as being "very tall", but is presented as a human queen, a descendant of a Greek king, not a mythological creature.

The Albina myth is also found in some later manuscripts of Wace's ''Roman de Brut'' (1155), attached as a prologue.

Scota

Scota, in Scottish mythology, and pseudohistory, is the name given to the mythological daughter of an Egyptian Pharaoh to whom the Gaels and Scots traced their ancestry. Scota first appeared in literature from the 11th or 12th century and most modern scholars interpret the legends surrounding her to have emerged to rival Geoffrey of Monmouth's claims that the descendants of Brutus (through Albanactus) founded Scotland. However some early Irish sources also refer to the Scota legends and not all scholars regard the legends as fabrications or as political constructions. In the Scottish origin myths, Albanactus had little place and Scottish chroniclers (e.g., John of Fordun and Walter Bower) claimed that Scota was the eponymous founder of Scotland and the Scots long before Albanactus, during the time of Moses.

Monarchs derived from Geoffrey of Monmouth

Geoffrey synchronises some of his monarchs with figures and events from the Bible, Greek, Roman and Irish legends, and recorded history. These are given in the "Synchronisation" column of the table below. Geoffrey dated Brutus' arrival in Britain (and subsequent founding of the Trojan-British monarchy) to 1115 BC. Geoffrey's book was later retold by Wace (in French) and Layamon (in Middle English); the final column represents Layamon's version.

After the death of Cadwallader, the kings of the Brythons were reduced to such a small domain that they ceased to be kings of the whole Brythonic-speaking area. Two of his relatives, Yvor and Yni, led the exiles back from Brittany, but were unable to re-establish a united kingship. The Anglo-Saxon invaders ruled the south-eastern part of the island of Great Britain, which would become England, after that point in time under the Bretwaldas and later the kings of England. The heirs to the Celtic-British throne continued through the Welsh kings of Gwynedd until that line was forced to submit itself to the Plantagenets in the 13th century. Princes and lords of Gwynedd ruled until the reign of Dafydd III, who ruled from 1282 to 1283. His death marked the end of the house of Brutus. Owen Tudor, grandfather of Henry VII of England, was a maternal descendant of the kings of Gwynedd; Henry's marriage with Elizabeth of York thus signified the merging of the two royal houses (as well as the feuding houses of York and Lancaster).

Forgeries

Pseudo-Berossus

Annius of Viterbo in 1498 claimed to have found ancient fragments from Berossus detailing the earliest settlement of 'Celtica', including the British Isles, by Samothes, a son of Japheth, son of Noah, after the Great Flood. These fragments were later revealed to have been forged by Annius himself, and are now known as "Pseudo-Berossus". The fragments can be found in Asher (1993) and include a king list. Before being revealed as a hoax, the list found its way into John Bale's ''Illustrium majoris Britanniae scriptorum'' (1548), John Caius' ''Historia Cantabrigiensis Academiae'' (1574), William Harrison's ''Description of England'' (1577), ''Holinshed's Chronicles'' (1587) and Anthony Munday's ''A briefe chronicle'' (1611).

Iolo Morganwg's Welsh Kings

Iolo Morganwg, between 1801 and 1807, published a series of Welsh Triads he claimed to have discovered in manuscript form, with the help of the antiquarian William Owen Pughe. These were later revealed to be a mixture of forgeries by Morganwg and Williams' alterations to authentic triads. Exactly how much "authentic" content there is of Morganwg's published work remains disputed by scholars today. Morganwg's triads describe the earliest occupation of Britain (Prydain) and contain a pseudo-historical reign of kings, beginning with Hu Gadarn, the "Plough King".

Hu Gadarn is described by Morganwg in his triads as being the earliest inhabitant of Britain having travelled from the "Summerland, called ''Deffrobani'', where Constantinople now stands" in 1788 BC. He is credited as having founded the first civilisation in Britain and introduced agriculture. Morganwg's ''Barddas'' (1862, p. 348) further states that this king is descended from Hu, but that, after a huge flood (see Afanc), only two people, ''Dwyfan'' and ''Dwyfach'', survived from whom the later inhabitants of Britain descended. The Welsh clergyman Edward Davies included this myth in his ''Celtic Researches on the Origin, Traditions and Languages of the Ancient Britons'' (1804):

Several 19th-century Christian authors—for example, Henry Hoyle Howorth—interpreted this myth to be evidence for the Biblical flood of Noah, yet in Morganwg's chronology ''Dwyfan'' and ''Dwyfach'' are dated to the 18th or 17th century BC, which does not fit the Biblical estimate for the Noachian deluge.

Tea Tephi

Tea Tephi is a legendary princess found described in British Israelite literature from the 19th century. Revd F. R. A. Glover, M.A., of London in 1861 published ''England, the Remnant of Judah, and the Israel of Ephraim'' in which he claimed Tea Tephi was one of Zedekiah's daughters. Since King Zedekiah of Judah had all his sons killed during the Babylonian Captivity, no male successors could continue the throne of King David, but, as Glover noted, Zedekiah had daughters who escaped death (Jeremiah 43:6). Glover believed that Tea Tephi was a surviving Judahite princess who had escaped and travelled to Ireland, and who married a local High King of Ireland in the 6th century BC who subsequently became blood linked to the British monarchy. This theory was later expanded upon by Rev. A.B. Grimaldi, who published in 1877 a successful chart entitled ''Pedigree of Queen Victoria from the Bible Kings'' and later by W.M.H. Milner in his booklet ''The Royal House of Britain an Enduring Dynasty (1902, revised 1909). Charles Fox Parham also authored an article tracing Queen Victoria's lineage back to King David (through Tea Tephi) entitled ''Queen Victoria: Heir to King David's Royal Throne''.

The Tea Tephi-British monarchy link is also found in J. H. Allen