Almohad campaign against Portugal (1190–1191)

The Almohad Caliphate launched a major offensive against the Kingdom of Portugal in the spring of 1190 that lasted into the summer of 1191.

The campaign of 1191 reversed Portugal's recent reconquests, captured Silves after a second siege and pushed the frontier north to the Tagus.

[1][2] In September 1189, Silves was captured by King Sancho I of Portugal with help from some crusaders on their way to join the siege of Acre.

[3] The Bayān al-mughrib of Ibn ʿIdhārī reports that around this time he defeated a fleet of northern crusaders near the Strait of Gibraltar, capturing many and receiving praise from the poets.

The caliph, however, left operations in the hands of local troops and took most of his expeditionary force to Córdoba.

[1] At Córdoba, the caliph met an embassy from King Alfonso VIII of Castile, with whom he signed a truce, freeing himself to concentrate on Portugal.

[6] The other nine ships of the fleet landed at Lisbon while King Sancho was preparing to march in defence of Santarém.

With their arrival, Sancho rebuffed al-Manṣūr's offer of a seven-year truce, which would have required surrendering Silves.

[7] Facing stronger resistance than anticipated, the caliph abandoned Tomar and Santarém and retreated south.

[2] After falling ill, al-Manṣūr decided to break off the siege of Silves, whose attackers were running short on supplies in any case.

[1][9] He had pushed the border north as far as the Tagus, leaving Portugal only one significant fortress to its south, at Évora.