In Arthurian legend, Morgause or Morgase (also known as Anna-Morgause or Ann-Morgause) is the half-sister of King Arthur who slept with him and produced Mordred, the incestuous heir that would lead to Camelot's downfall. She is the daughter of Gorlois, Duke of Cornwall and Lady Igraine. She is married to King Lot, an enemy of Arthur in the rebellions following Arthur's coronation. King Arthur is an important figure in the mythology of Britain. ... King Arthur is an important figure in the mythology of Great Britain, where he appears as the ideal of kingship in both war and peace. ... This entry is on the King Arthur character. ... Camelot is the name of the stronghold of the legendary King Arthur, from which he fought many of the battles that made up his life. ... In the legendary tales of King Arthur, Gorlois was the Duke of Cornwall and married to the beautiful Ygerna (Igraine or Ygraine). ... The Dukedom of Cornwall was the first dukedom created in the peerage of England. ... In Arthurian legend, Igraine is the mother of King Arthur. ... Lot in Arthurian Legend was the king of Lothian, Orkney, and Norway which leads to his name which essentially means King of Lothian. He is the father of most popularly Gawain, Gareth, and in Welsh tradition, Mordred. ... A coronation is a ceremony marking the investment of a monarch with regal power through, amongst other symbolic acts, the placement of a crown upon his or her head. ...

She has several siblings:

• Elaine, her sister
• Morgan le Fay, her sister
• King Arthur, her half-brother from her mother's affair with Uther Pendragon

She has five children, all sons. From eldest to youngest they are: Elaine (a form of Helen) is a name shared by several different characters in Arthurian Legend. ... Morgan le Fay, by Anthony Frederick Sandys (1829 - 1904), 1864 (Birmingham Art Gallery): A spell-brewing Morgaine distinctly of Tennysons generation In the mythology of King Arthur, Morgan le Fay, alternatively known as Morgaine, Morgain or Morgana and a slew of related name variants, is a powerful sorceress and... King Arthur is an important figure in the mythology of Great Britain, where he appears as the ideal of kingship in both war and peace. ... Uther Pendragon (pen-dragon = head of the dragons) is the legendary father of King Arthur in Arthurian legend. ...

• Gawain, who becomes one of King Arthur's greatest knights
• Agravaine
• Gaheris
• Gareth
• Mordred, her son with Arthur

Her children play key roles in the story of Arthur and his kingdom. She is active in Thomas Malory's Le Morte d'Arthur, and the Vulgate and Post-Vulgate versions of Merlin. Sir Gawain and the Green Knight In Arthurian legend, Sir Gawain (Gawan, Gauvain, Walewein etc. ... Sir Agravain or Sir Agravaine was a knight of the Round Table in Arthurian legend. ... Gaheris is a figure of Arthurian legend, a knight of the Round Table. ... Sir Gareth was a Knight of the Round Table in Arthurian Legend. ... This entry is on the King Arthur character. ... Sir Thomas Malory (c. ... Le Morte dArthur (The Death of Arthur)—the title is actually spelled as Le Morte Darthur in the first printing and also in some modern editions—is Sir Thomas Malorys compilation of some French and English Arthurian romances. ... The Lancelot-Grail, also known as the prose Lancelot, the Vulgate Cycle, or the Pseudo-Map Cycle, is a major source of Arthurian legend. ... The Post-Vulgate Cycle is one of the major Old French prose cycles of Arthurian literature. ...

In Le Morte d'Arthur and the Post-Vulgate, her husband is killed by King Pellinore in battle, starting a blood feud between the families of Pellinore and Lot. Pellinore is killed by Gawain and Gaheris, and Morgause later has an affair with Lamorak, son of Pellinore and one of the best knights of the Round Table. Her son Gaheris catches them together, and kills Morgause in bed, though he lets Lamorak go. Thinking it is Lamorak that killed their mother, Gawain, Agravain, Gaheris and Mordred (Gareth takes no part) ambush Lamorak and kill him. The brothers do eventually find out that Gaheris was the real killer, and he is banished from the court (though he appears later in the narrative). King Pellinore of Listinoise is a minor character in Arthurian legend. ... Sir Lamorak was the son of King Pellinore and the brother of Sir Percivale. ... For other uses, see Round Table (disambiguation). ...

In modern variations, Morgause's character is sometimes combined with Morgan le Fay's, and her role as the mother of Mordred is transferred to Morgan.