The Battle of Lepanto is fought, and the Ottoman Navy suffers its first defeat.

The Battle of Lepanto was a naval engagement that took place on 7 October 1571 when a fleet of the Holy League, a coalition of Catholic states arranged by Pope Pius V and led by the navies of the Spanish Empire and the Republic of Venice, inflicted a major defeat on the fleet of the Ottoman Empire in the Gulf of Patras. The Ottoman forces were sailing westward from their naval station in Lepanto when they met the fleet of the Holy League which was sailing east from Messina, Sicily.