The Count of Boulogne was a title held by rulers of the region of Boulogne-sur-Mer in northern France. This title emerged in the early medieval period and was often associated with the local nobility. The Counts played a significant role in the feudal system, managing lands and providing military support to the king. The most notable Count of Boulogne was Eustace II, who lived in the 11th century. He was known for his involvement in the First Crusade and for founding the Abbey of Boulogne. The title eventually became part of the larger Duchy of Brittany and lost its independent significance over time.