Sir Meliot de Logres (which in this case probably refers to London rather than England) was the son of Marin the Jealous and brother of Sir Brian of the Isles. Marin murdered his wife and Meliot thus fled to a hermitage on his uncle’s land. He later moved on to the Lion Field, named after his pet which was slain by Sir Clamadoz of the Shadows. Meliot killed him in revenge.
The London knight rode with his brother in an attempt to rescue their cousin, the Lady of the Lake, from Sir Hontzlake of Wendland. Unfortunately they failed in their quest, but managed to impede the knight for long enough to enable Sir Pellinore to succeed in their place. It was Nabigan of the Rock, however, who pushed Meliot into the Court of King Arthur, when he murdered the knight’s father and then tried to take Meliot’s lands. Sir Gawain became his champion and defeated Nabigan. Meliot repaid the favor some time later when he raised the siege imposed on Arthur and Gawain by Anurez the Bastard.
In his subsequent battle with Sir Gilbert the Bastard, Meliot was fatally wounded and was only saved by Sir Lancelot braving the Chapel Perilous in order to obtain a holy cloth or sword required to heal him. Not surprisingly, Meliot became a Knight of the Round Table and attended the Winchester Tournament. However, during the dark days of Lancelot’s affair with Queen Guinevere, he joined in Sirs Mordred and Agravaine's plans to trap them together. He was killed as Lancelot made good his escape (or else was killed by Sir Brudan). He may be identical to Sir Meliant de Liz, although their fathers differ and they sometimes appear in company together.