Prose Tristan in the context of "Tristan and Iseult"

Agravain or Agravaine (/ˈæɡrəveɪn/ AG-rə-vain) 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.

Tristan (Latin/Brythonic: Drustanus; Welsh: Trystan; Italian: Tristano, Portuguese: Tristão; Spanish: Tristán), also known as Tristran or Tristram and similar names, is the folk hero of the legend of Tristan and Iseult. While escorting the Irish princess Iseult to wed Tristan's uncle, King Mark of Cornwall, Tristan and Iseult accidentally drink a love potion during the journey and fall in love, beginning an adulterous relationship that eventually leads to Tristan's banishment and death.

The character's first recorded appearance is in the 12th-century poetic tellings initiated by Béroul and Thomas of Britain, which were eventually vastly expanded in the later tradition from the vast Prose Tristan. In later versions of his story he is featured in Arthurian legend, including the seminal compilation Le Morte d'Arthur, as a great Knight of the Round Table and friend of Lancelot.

The Post-Vulgate Cycle, also known as the Post-Vulgate Arthuriad, the Post-Vulgate Roman du Graal (Romance of the Grail) or the Pseudo-Robert de Boron Cycle, is one of the major Old French prose cycles of Arthurian literature from the early 13th century. It is considered essentially a rewriting of the earlier and more popular Vulgate Cycle (also known as the Lancelot-Grail cycle), with much left out but also much added, including characters and scenes from the Prose Tristan. The cycle did not survive in its entire original form, but has been reconstructed from fragments in several medieval languages.