Agravain is a Knight of the Round Table in Arthurian legend, whose first known appearance is in the works of Chrétien de Troyes. He is the second eldest son of King Lot of Orkney with one of King Arthur's sisters known as Anna or Morgause, thus nephew of King Arthur, and brother to Sir Gawain, Gaheris, and Gareth, as well as half-brother to Mordred. Agravain secretly makes attempts on the life of his hated brother Gaheris starting in the Vulgate Cycle, participates in the slayings of Lamorak and Palamedes in the Post-Vulgate Cycle, and murders Dinadan in the Prose Tristan. In the French prose cycle tradition included in Thomas Malory's Le Morte d'Arthur, together with Mordred, he then plays a leading role by exposing his aunt Guinevere's affair with Lancelot, which leads to his death at Lancelot's hand.

The Lancelot-Grail Cycle, also known as the Vulgate Cycle or the Pseudo-Map Cycle, is an early 13th-century French Arthurian literary cycle consisting of interconnected prose episodes of chivalric romance originally written in Old French. The work of unknown authorship, presenting itself as a chronicle of actual events, retells the legend of King Arthur by focusing on the love affair between Lancelot and Guinevere, the religious quest for the Holy Grail, and the life of Merlin. The highly influential cycle expands on Robert de Boron's "Little Grail Cycle" and the works of Chrétien de Troyes, previously unrelated to each other, by supplementing them with additional details and side stories, as well as lengthy continuations, while tying the entire narrative together into a coherent single tale. Its alternate titles include Philippe Walter's 21st-century edition Le Livre du Graal.