William the Lion sometimes styled William I, also known by the nickname Garbh, "the Rough", (c 1143 – 4 December 1214) reigned as King of the Scots from 1165 to 1214. His reign was the second longest in Scottish history before the Act of Union

Acts of Union 1707

The Acts of Union were two Parliamentary Acts - the Union with Scotland Act passed in 1706 by the Parliament of England, and the Union with England Act passed in 1707 by the Parliament of Scotland - which put into effect the terms of the Treaty of Union that had been agreed on 22 July 1706,...

 with England

England

England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...

 in 1707, (James VI

James I of England

James VI and I was King of Scots as James VI from 24 July 1567 and King of England and Ireland as James I from the union of the English and Scottish crowns on 24 March 1603...

's was the longest 1567–1625). He became King following his brother Malcolm IV

Malcolm IV of Scotland

Malcolm IV , nicknamed Virgo, "the Maiden" , King of Scots, was the eldest son of Earl Henry and Ada de Warenne...

's death on 9 December 1165 and was crowned on 24 December 1165.

In contrast to his deeply religious, frail brother, William was powerfully built, redheaded, and headstrong.