In the medieval romance Lanzelet, Lancelot (Lanzelet) marries four different women, one after the other until settling down permanently with the third who was named Iblis. Lanzelet fathered on her a daughter and three sons who inherited Lanzelet's lands.

In the French Arthurian romances which tell anything about Lancelot's love life, Lancelot was the lover of Queen Guenevere. According to the Prose Lancelot from the time when Lancelot first met Queen Guenevere Lancelot was totally in love with her and desired no other woman and had no desire to wed any save Guenevere whom he could not have as his wife since she was married to King Arthur.

In the medieval romance Lanzelet, Lancelot (Lanzelet) marries four different women, one after the other, and then settles down permanently with the third who was named Iblis. This is the only account in which Lancelot is married.

In most medieval romances that get into Lancelot's love life, Lancelot was Queen Guenevere's lover and had no romantic interest in any other woman.

It all depends on which strand of the legends you are reading. In many of the more modern tales, Mordred is his illegitimate son from a relationship he had with his own half-sister.

Another son given to Arthur in various tales is named Lohot, sometimes identified as the son of Arthur and Guenevere, sometimes as an illegitimate son of Arthur by a woman named Lionors. Sir Thomas Malory calls him Borre and Bohart in his Le Morte d'Arthur and name his mother as Lisanor.

Then there is Arthur the Little who is an illegitimate son of King Arthur in the Post-Vulgate Arthurian Cycle.

There is Illinot who is an illegitimate son of Arthur in Wolfram von Eschanbach's Parzival.

Welsh tradition supplies Llacheu, who is possibly identical to Lohot, Gwydre, and Amhar/Amir whom Arthur is said to have slain.

According to the Irish tale of Melora and Orlando, Melora was King Arthur's daughter. The Icelandic Thiðrekssaga gives King Arthur a daughter named Hilde.

Some traditional medieval genealogies trace the highland clans of MacArthur and Campbell to a certain Smervie who is said to the son to King Arthur.

And a few other sons or daughters of Arthur are mentioned in later texts and invented by modern authors.