King Arthur's family
King Arthur's family grew throughout the centuries with King Arthur's legend. Several of the legendary members of this mythical king's family became leading characters of mythical tales in their own right.
Medieval Welsh tradition
In Welsh Arthurian pre-Galfridian tradition, that is from before the time of Geoffrey of Monmouth's 12th-century Historia Regum Britanniae, Arthur was granted numerous relations and family members. Several early Welsh sources are usually taken as indicative of Uther Pendragon being known as Arthur's father before Geoffrey wrote, with Arthur also being granted a brother and a nephew in these texts. Arthur also appears to have been assigned a sister in this material – Gwalchmei is named as his sister-son in Culhwch and Olwen, his mother being one Gwyar. Culhwch and Olwen, the Vita Iltuti and the Brut Dingestow combine to suggest that Arthur's own mother was named Eigyr.The genealogies from the 13th-century Mostyn MS. 117 assert that Arthur is the son of Uthyr, the son of Custennin, the son of Cynfawr, the son of Tudwal, the son of Morfawr, the son of Eudaf, the son of Cadwr, the son of Cynan, the son of Caradoc, the son of Bran, the son of Llŷr. Regarding Arthur's own family, his wife is consistently stated to be Gwenhwyfar, usually the daughter of King Ogrfan Gawr and sister to Gwenhwyach, although Culhwch and Bonedd yr Arwyr do indicate that Arthur also had some sort of relationship with Eleirch daughter of Iaen, which produced a son named Kyduan. Kyduan was not the only child of Arthur according to Welsh Arthurian tradition – he is also ascribed sons called Amr, Gwydre, Llacheu and Duran.
In addition to this immediate family, Arthur was said to have had a great variety of more distant relatives, including maternal aunts, uncles, cousins and a grandfather named Anlawd Wledig. The latter is the common link between many of these figures and Arthur: thus the relationship of first cousins that is implied or stated between Arthur, Culhwch, Illtud, and Goreu mab Custenhin depends upon all of their mothers being daughters of this Anlawd, who appears to be ultimately a genealogical construct designed to allow such inter-relationships between characters to be postulated by medieval Welsh authors. Arthur's maternal uncles in Culhwch and Olwen, including Llygatrud Emys, Gwrbothu Hen, Gweir Gwrhyt Ennwir and Gweir Baladir Hir, similarly appear to derive from this relationship.
Other medieval literature
Relatively few members of Arthur's family in the Welsh materials are carried over to the works of Geoffrey of Monmouth and chivalric romancers. His grandfather Anlawd Wledic and his maternal uncles, aunts and cousins do not appear there, and neither do any of his sons or his paternal relatives. Only the core family seem to have made the transition: his wife Gwenhwyfar, his father Uther, his mother and his sister-son Gwalchmei. Gwalchmei's mother – Arthur's sister – failed to make the journey, Gwyar's place being taken by Anna, the wife of Loth, in Geoffrey's account, whilst Medraut is made into a second sister-son for Arthur.by W. H. Margetson
In addition, new family members enter the Arthurian tradition from this point onwards. Uther is given a new family, including two brothers and a father, while Arthur gains a sister or half-sister, Morgan, first named as his relative by Chrétien de Troyes in Yvain. A new son of Arthur, named Loholt, is introduced in Chrétien's Erec and Enide. Another significant new family-member is Arthur's other sister or half-sister initially known as Orcades, the daughter of Gorlois and Igerna and mother of Gawain and Mordred in the romances. A third half-sister, Elaine, is also added at this time. Through the sisters, Arthur is given further nephews, who all become Knights of the Round Table. Various works also mention or feature his nieces.
There are furthermore various other more distant family members, such as the case of the historical Romano-British leader Ambrosius Aurelianus being turned into his uncle in Goeffrey's tradition deriving Arthur's lineage from the self-proclaimed Western Roman Emperor Constantine II of Britain, who in this version of the legend is presented as Arthur's grandfather. One important figure of no actual blood relation to Arthur is Ector, who in the stories of Arthur's incognito youth is often secretly his adoptive father following the death of Uther soon after his birth.
Offspring
Although Arthur is given sons in both early and late Arthurian tales, he is rarely granted significant further generations of descendants. This is at least partly because of the premature deaths of his sons, who in the later tradition usually include Mordred. Sometimes, including in Le Morte d'Arthur, Guinevere's failure to produce a legitimate heir contributes to the fall of Arthur.Amr is the first to be mentioned in Arthurian literature, appearing in the 9th-century Historia Brittonum: "There is another wonder in the region which is called Ercing. A tomb is located there next to a spring which is called Licat Amr; and the name of the man who is buried in the tomb was called thus: Amr. He was the son of Arthur the soldier, and Arthur himself killed and buried him in that very place. And men come to measure the grave and find it sometimes six feet in length, sometimes nine, sometimes twelve, sometimes fifteen. At whatever length you might measure it at one time, a second time you will not find it to have the same length – and I myself have put this to the test." Why Arthur chose to kill his son is never made clear. The only other reference to Amr comes in the post-Galfridian Welsh romance Geraint, where "Amhar son of Arthur" is one of Arthur’s four chamberlains along with Bedwyr's son Amhren.
Gwydre is similarly unlucky, being slaughtered by the giant boar Twrch Trwyth in Culhwch and Olwen, along with two of Arthur's maternal uncles - no other references to either Gwydre or Arthur's uncles survive. Another son, known only from a possibly 15th-century Welsh text, is said to have died on the field of Camlann:
More is known of Arthur's son Llacheu. He is one of the "Three Well-Endowed Men of the Island of Britain", according to the Triad 4, and he fights alongside Cei in the early Arthurian poem Pa gur yv y porthaur?. Like his father is in Y Gododdin, Llacheu appears in the 12th-century and later Welsh poetry as a standard of heroic comparison and he also seems to have been similarly a figure of local topographic folklore too. Taken together, it is generally agreed that all these references indicate that Llacheu was a figure of considerable importance in the early Arthurian cycle. Nonetheless, Llacheu too dies, with the speaker in the pre-Galfridian poem Ymddiddan Gwayddno Garanhir ac Gwyn fab Nudd remembering that he had "been where Llacheu was slain / the son of Arthur, awful in songs / when ravens croaked over blood."
The romances' Loholt usually appears as a son by Guinevere in the works such as Lanzelet and Perlesvaus, but in the Vulgate Cycle he is Arthur's illegitimate son by Lyzianor. He is treacherously killed by Kay so that the latter can take credit for the defeat of the giant Logrin in Perlesvaus, and dies from illness in the Vulgate. Thomas Malory apparently renamed him as Borre le Cure Hardy, conflating him with another character from the French texts.
Medraut/Mordred is an exception to this tradition of a childless death for Arthur's sons. Mordred, like Amr, is killed by Arthur – at Camlann – according to Geoffrey of Monmouth and the post-Galfridian tradition but, unlike the others, he is ascribed two sons, both of whom rose against Arthur's successor and cousin Constantine III with the help of the Saxons. However, in Geoffrey's Historia, Mordred was not yet actually Arthur's son. His relationship with Arthur was once more reinterpreted in the Vulgate Cycle, as he was made the result of an unwitting incest between Arthur and his sister. This tale is preserved in the later romances, with the motif of Arthur knowing that Mordred would grow up to kill him, and so by the time of Malory's Le Morte d'Arthur Arthur has devised a plot, Herod-like, to kill all children born on the same day as Mordred in order to try to save himself from this fate.
Later literature has expanded Arthur's family further. Richard Johnson's 16th-century romance Tom a Lincoln adds another illegitimate son, the eponymous Tom. Through Tom, Arthur is also given grandsons referred to only as the Black Knight and Faerie Knight. Other works, such as Henry Fielding's Tom Thumb, Walter Scott's The Bridal of Triermain and modern adaptations of Arthurian legend, have occasionally given Arthur daughters, diverging from the earlier legends.