William the Lion

William the Lion, sometimes styled William I, also known by the nickname Garbh, "the Rough", (c. 1142 – 4 December 1214) reigned as King of Scots from 1165 to 1214 (49 years). He had the second-longest reign in Scottish history before the Act of Union with England in 1707. James VI (reigned 1567–1625) would have the longest.