William, Lord of Douglas (c. 1220 – c. 1274), known as 'Longleg', was a Scottish nobleman. He was the son of Archibald I, Lord of Douglas. The years of the minority of King Alexander III (1249–1262) featured an embittered struggle for the control of affairs between two rival parties, the one led by the nationalistic Walter Comyn, Earl of Menteith, the other by pro-English Alan Durward, Justiciar of Scotia. The former dominated the early years of Alexander's reign. In 1255 an interview between the English and Scottish kings at Kelso led to Menteith and his party losing to Durward's party. Later both parties called a Meeting of the great Magnates of the Realm to establish a regency until Alexander came of age. William Lord of Douglas was one of the magnates called to witness. Douglas was a p