Roger II of Sicily was a Norman king who ruled from 1130 to 1154. He is known for uniting various territories in southern Italy and establishing the Kingdom of Sicily. His reign marked a period of cultural and economic prosperity, as he promoted trade and the arts. Roger II was also notable for his religious tolerance, allowing different faiths to coexist in his kingdom. He built the famous Palermo Cathedral and the Palatine Chapel, showcasing a blend of architectural styles. His leadership laid the foundation for a powerful and diverse realm in the Mediterranean region.