 During this period, Almohad forces under the command of caliph Abū Yūssuf Yaʿqūb bin Yūssuf al-Manṣūr following their conquest of the Algarve, advanced to the north, expelling Portuguese forces from citadels in Alcácer do Sal and Palmela, and destroyed the defensive lines in Almada (1191).The Portuguese monarch reconquered the fortifications in 1195, and began the construction of a castle on the site.It was only following the battle of Navas de Tolosa (1212), when Christian forces registered a decisive victory over Muslim forces in the Iberian peninsula, that the lost territories were recaptured from the Tagus to Évora.