When the Fitna of al-Andalus broke out and the Umayyad Caliphate of Cordova fragmented into numerous taifa states, Dom Sesnando Davides, lord of Tentúgal proposed the conquest of the city to Ferdinand of Leon.

[1] Ferdinand thus began preparations for the campaign in December 1063, after receiving the remains of Saint Isidore of Seville in León.

They advanced through a coastal road that linked Santiago de Compostela to Iria Flavia to Braga, Porto and Coimbra.

With food supplies running low in the city, it was violently taken by storm, with many killed and 5000 Muslims taken captive.

[3] The city would become an important settlement place for Mozarabs (Portuguese: moçárabes) arriving from Muslim lands to the south.