The title "Duke of Apulia" refers to a noble rank historically associated with the region of Apulia in southern Italy. The title emerged during the Middle Ages, particularly in the context of the Norman conquests. It was often held by rulers who governed the area and played a significant role in the political landscape of the time. The title has been linked to various noble families, including the House of Hauteville, which was prominent in the 11th century. Over time, the title's significance diminished, but it remains a notable part of Italian history and aristocracy, reflecting the region's rich cultural heritage.