William V of Aquitaine, also known as William the Great, was a prominent nobleman in the 11th century. He ruled the vast region of Aquitaine in southwestern France from 1030 until his death in 1086. William was known for his efforts to strengthen the power of the duchy and for his patronage of the Church, which helped to enhance his influence. During his reign, William V played a significant role in the political landscape of medieval France. He was involved in various alliances and conflicts, particularly with neighboring regions. His legacy includes the promotion of cultural and economic development in Aquitaine, contributing to its importance in the feudal system.