Reconquista: Forces under Afonso I of Portugal captured Lisbon from the Moors after a four-month siege in one of the few Christian victories during the Second Crusade. Siege of Lisbon: The siege of Lisbon, from 1 July to 25 October 1147, was the military action against the Almoravid dynasty that brought the city of Lisbon under the definitive control of the new Christian power, the Kingdom of Portugal. October 25, 1147. Wiki link