William IX of Aquitaine was a prominent nobleman and poet from the 11th century, known for being the Duke of Aquitaine. He was born around 1071 and ruled from 1086 until his death in 1126. William was notable for his military prowess and played a significant role in the politics of medieval France, often engaging in conflicts with neighboring territories. In addition to his political influence, William IX is recognized as one of the earliest troubadours, contributing to the development of Occitan poetry. His works often explored themes of love and chivalry, reflecting the cultural shifts of his time. William's legacy includes his descendants, notably Eleanor of Aquitaine, who became a powerful figure in her own right.