In the medieval stories about King Arthur (see Arthur and Arthurian legend), Sir Lancelot of the Lake (du Lac) was King Arthur's bravest knight.

As a baby he was rescued from a lake by Morgan Le Fay, who prepared him to receive his surname--Lancelot. He was descended from kings named Galahad and was the father of Sir Galahad.

When grown, Lancelot superseded Sir Gawain, as Arthur's champion. In later versions of the legend, Lancelot committed adultery with Queen Guinevere.

Always a champion of women, he frequently saved her from danger. He eventually left Arthur's court altogether.

The legend of Lancelot seems to have originated in ancient Ireland, where he was the Gaelic sun-god of summer, known at Tara as Lugh (Lug) Lamfada.