The Battle of Lisbon took place in 1580 during the Iberian Union, a conflict over the Portuguese crown. It was part of a larger struggle between the Spanish and Portuguese empires, following the death of King Sebastian of Portugal without an heir. The battle was fought between the forces of Philip II of Spain and those loyal to the Portuguese nobility, who sought to maintain their independence. The battle ended with a decisive victory for the Spanish, leading to the annexation of Portugal into the Spanish Empire. This union lasted for 60 years, significantly impacting the political landscape of Europe and the global influence of both nations.