Lot of Lothian

Lot or Loth /ˈlɒt/ is the king of Lothian in the Arthurian legend. He is best known as the father of Sir Gawain. Such a ruler first appeared late in the 1st millennium's hagiographical material concerning Saint Kentigern (also known as Saint Mungo), which feature a Leudonus, king of Leudonia, a Latin name for Lothian. In the 12th century, Geoffrey of Monmouth adapted this to Lot, king of Lothian, in his influential chronicle Historia Regum Britanniae, portraying him as King Arthur's brother-in-law and ally. In the wake of Geoffrey's writings, Lot appeared regularly in later romance.

Lot chiefly figures as king of Lothian, but in other sources he also rules Orkney and sometimes Norway. He is generally depicted as the husband of Arthur's sister or half-sister, variously named Anna or Morgause. The names and number of his children vary depending on the source, but the later romance tradition gives him the sons Gawain, Agravain, Gaheris, Gareth, and Mordred.

A king of Lothian appears in both early Latin and Welsh sources. An early fragmentary Life of St Kentigern contains a Leudonus of Leudonia as the maternal grandfather of Saint Kentigern, also known as Mungo. In this text, Leudonus becomes enraged when he discovers that his daughter, Kentigern's mother Teneu, has been impregnated by Owain mab Urien, and has her thrown from a cliff. However, she survives the ordeal with divine protection and goes to Saint Serf's community, where she gives birth to Kentigern.

...
Wikipedia