William II of Sicily, also known as William the Good, was the King of Sicily from 1166 until his death in 1189. He was the son of William I of Sicily and Margaret of Navarre. His reign is noted for its relative peace and prosperity, as well as efforts to strengthen the kingdom's administration and economy. William II was a patron of the arts and architecture, contributing to the cultural development of Sicily. He is also remembered for his attempts to maintain the independence of Sicily amidst the political pressures from the Papacy and the Holy Roman Empire.