 With a further series of battles and deposings, five of Malcolm's sons as well as one of his brothers successively became king. Eventually, the Crown came to his youngest son, David. David was succeeded by his grandsons Malcolm IV, and then by William the Lion, the longest-reigning King of Scots before the Union of the Crowns. William participated in a rebellion against King Henry II of England but when the rebellion failed, William was captured by the English. In exchange for his release, William was forced to acknowledge Henry as his feudal overlord. The English King Richard I agreed to terminate the arrangement in 1189, in return for a large sum of money needed for the Crusades. William died in 1214, and was succeeded by his son Alexander II. Alexander II, as well as his successor Alexander III, attempted to take over the Western Isles, which were still under the overlordship of Norway. During the reign of Alexander III, Norway launched an unsuccessful invasion of Scotland; the ensuing Treaty of Perth recognised Scottish control of the Western Isles and other disputed areas.
