The Counts of Portugal were noble titles held by the rulers of the region before it became a kingdom. The title was first established in the 9th century, during the period of the Reconquista, when Christian kingdoms sought to reclaim territory from Muslim rule. The most notable count was Count Henry of Portugal, who played a significant role in the early formation of the region. In 1139, Afonso I declared himself king, marking the transition from counts to kings in Portugal's history. This change solidified the political structure and laid the foundation for the Kingdom of Portugal, which would grow to become a significant maritime power in the Age of Discovery.