Gawain (English: /ɡəˈweɪn/, Welsh: [ˈɡawain]; also called Gwalchmei, Gualguanus, Gauvain, Walwein, etc.) is King Arthur's nephew and a Knight of the Round Table in the Arthurian legend. Under the name Gwalchmei, he appears very early in the legend's development, being mentioned in some of the earliest Welsh Arthurian sources.
He is one of a select number of Round Table members to be referred to as one of the greatest knights, most notably in Sir Gawain and the Green Knight. He is almost always portrayed as the son of Arthur's sister Morgause (or Anna) and King Lot of Orkney and Lothian, and his brothers are Agravain, Gaheris, Gareth, and Mordred. He was well known to be the most trustworthy friend of Sir Lancelot. In some works, Sir Gawain has sisters as well. According to some legends, he would have been the true and rightful heir to the throne of Camelot, after the reign of King Arthur.
Gawain is often portrayed as a formidable, courteous, and also a compassionate warrior, fiercely loyal to his king and family. He is a friend to young knights, a defender of the poor, and as "the Maidens' Knight", a defender of women as well. In some works, his strength waxes and wanes with the sun; in the most common form of this motif, his might triples by noon, but fades as the sun sets. His knowledge of herbs makes him a great healer, and he is credited with at least three children: Florence, Lovell, and Gingalain, the last of which is also called Libeaus Desconus or Le Bel Inconnu, the Fair Unknown. Gawain appears in English, French and Celtic literature as well as in Italy where he appears in the architecture of the north portal in the cathedral of Modena, constructed in 1184.