The King Arthur Family Tree, Explained

Arthur's family tree is short and it is a trap. Four blood relatives matter — a father, a mother, a half-sister, a son — and three of those four were hidden from him at the moment they counted. Everything else on this chart is a bond he chose: a foster brother, a first knight, a wife, a table of men sworn to each other. The legend is the story of chosen bonds losing to blood ones.

How to read this

Every card is a person and every line between two cards is a relationship you can click. The coloured bands separate the houses — Pendragon, Orkney, the Round Table, the Grail quest, the enchanters. Where no blood is involved the line says what it is instead: counsellor to, lover of, unwitting slayer of, betrayer of. Look at the shape before you read a word: the tree is two small families, and they are joined twice — once by a marriage, once by a night nobody admitted to.

Tintagel: the night that made a king and a lie

Uther wanted Igraine, who was married to Gorlois of Cornwall. Merlin gave Uther her husband's face for one night, and Gorlois was killed in the field the same night. Arthur was begotten on a woman who believed she was with her husband, and handed to Merlin before he could be weaned. Ector raised him thinking he was raising a squire. So the first three relationships on this chart are a disguise, a bereavement and an adoption — and the boy who grows up out of them does not know one of them.

The half-sisters, and the son

Igraine's daughters by Gorlois are Morgause and Morgan — Arthur's half-sisters, and strangers to him. Morgause is married north to King Lot and bears the four Orkney knights. Then she and Arthur lie together when neither knows the other's blood, and Mordred is the result: the son who takes the crown while his father is overseas and kills him for it. This is why the chart's most important line is not a marriage. It is the parent line from Arthur to Mordred, which runs straight back up into his own mother's house.

The four brothers of Orkney

Gawain, Agravain, Gaheris and Gareth are one family doing four different things to the same kingdom. Gawain is the courtliest man at the table and ends it by refusing to forgive. Agravain is the one who will not let the queen's affair stay unspoken, and his accusation is the crack the realm breaks along. Gareth arrives at court as a kitchen boy, serves a year before giving his name, is knighted by Lancelot — and killed by Lancelot, unarmed, in the rescue of the queen. So is Gaheris.

Lancelot, Guinevere, and the thing everyone knew

Guinevere brought the Round Table itself as her dowry — her father Leodegrance gave Arthur both the daughter and the hundred seats. Lancelot is the best knight in the world and the worst friend Arthur has, and the court can bear it exactly as long as nobody says it out loud. Agravain says it. After that the table has to choose, and it chooses badly in every direction.

The Grail: the son who was better than his father

Elaine of Corbenic won Lancelot for a single night by a trick and paid for it with his hatred. What came of that night is Galahad, who sits the Siege Perilous, sees the Grail whole, and asks to die — everything his father was not. Percival is the other kind of failure: raised in the woods knowing nothing, he reaches the Grail castle and loses it by not asking the question. The Grail quest is where the table empties. It is not an enemy that ends Camelot; it is the best knights leaving to look for something better.

The two enchanters

Merlin makes Arthur possible, makes him king, and sees his own end coming — then walks into it. Nimue, the Lady of the Lake, gives Arthur the sword and takes Merlin's freedom, having learned everything she knows from him first. And Morgan, set against her brother for years, is the one whose barge carries him away at the end. The chart puts all three on the same band, because magic in this story is never on one side.

Nephew or son: the oldest change in the story

Who is not on this chart

Tristan and Iseult, Yvain, Erec, Culhwch, the whole Welsh strand of Arthur's warband, and the dozens of knights Malory names once and drops. The table has a hundred seats and this board has twenty-four cards, so the cut is the people the family turns on: Tintagel, Orkney, the queen's house, and Lancelot's line. A chart with a hundred names is a chart nobody reads.