The House of Poitiers was a noble family in medieval France, known for its significant influence during the 10th to 12th centuries. It originated from the region of Poitou and played a crucial role in the politics of the time, often intermarrying with other powerful families to strengthen alliances. Members of the House of Poitiers included notable figures such as William IX of Aquitaine, a prominent duke and poet. The family's legacy is marked by its contributions to the cultural and political landscape of France, particularly in the context of the Plantagenet dynasty and the Crusades.