The Siege of Algeciras commences during the Spanish Reconquista.

The siege of Algeciras (1342–1344) was undertaken during the Reconquest of Spain by the Castillian forces of Alfonso XI assisted by the fleets of the Kingdom of Aragon and the Republic of Genoa. The objective was to capture the city of Algeciras, called Al-Jazeera Al-Khadra by the Arabs who occupied it. The city was the capital and the main port of the European territory of the Marinid Empire.

The Reconquista or the fall of al-Andalus was a series of military and cultural campaigns that European Christian kingdoms waged against Muslim-ruled al-Andalus, culminating in the reign of the Catholic Monarchs of Spain.