First king of Portugal (1128-1185), best known for the capture of Lisbon from its Muslim inhabitants on 24 October 1147 with the aid of crusaders bound for the Holy Land.
The son of Henry of Burgundy (named count of Portugal around 1097) and Teresa, illegitimate daughter of Alfonso VI of Castile (1065-1109), Afonso Henriques was only five years old on the death of his father (1112). Following his mother’s regency, Afonso began to exercise independent authority in 1128, styling himself king of Portugal after 1139. Four years later, he declared himself a liegeman of St. Peter, although the papacy did not formally recognize his kingship until 1179. During the 1140s Afonso worked to extend his authority into the Muslim-held regions south of the river Tagus. As part of his efforts, Afonso sought the support of the Templars, endowed by his mother with their first holdings in the region at Soure in 1128. The king’s initial assault on Lisbon, made with the assistance of English ships in 1140 or 1142, was a failure, but in the spring of 1147 he captured the nearby town of Santarém in preparation for another assault on Lisbon.
Earlier that year, Afonso had exchanged letters with Bernard of Clairvaux, who may have sought support for his campaign while preaching in Germany and the Low Countries. It is not clear when Afonso became aware of the fleet of Anglo-Norman, Flemish, and German crusaders departing for the Holy Land from Dartmouth in England in May 1147. However, when the fleet arrived at Oporto, arrangements were made for a meeting outside Lisbon between Afonso and the crusaders’ representatives, who agreed to assist in an assault on the city. After months of siege, the Muslims surrendered to the Portuguese king on 24 October. Much of Afonso’s subsequent reign was spent consolidating his gains and struggling against the Almohads. He died on 6 December 1185.
King Afonso I of Portugal. (Hulton-Deutsch Collection/Corbis)