The Spanish-held Castillo San Felipe del Morro in San Juan, Puerto Rico having been besieged for fifteen days, surrenders to an English force under Sir George Clifford, Earl of Cumberland.

Castillo San Felipe del Morro, most commonly known as El Morro, is a large fortress and citadel in the Old San Juan historic quarter of San Juan, the capital city and municipality of Puerto Rico. Commissioned by King Charles I of Spain in 1539, it was first built as a fortified tower in honor of King Philip II, who oversaw its expansion into a hornwork bastion fort by 1595. Over the next 200 years, especially in the reign of King Charles III, El Morro continued to be developed to reach its current form in 1787. Rising 43 metres (140 ft) from the Atlantic shoreline with 5.5 to 7.6 metres thick walls, the six-leveled edifice stands on a steep, rocky headland promontory on San Juan Islet guarding the entry to San Juan Bay, the harbor of Old San Juan. El Morro, alongside La Fortaleza, San Cristóbal, El Cañuelo, and other forts part of the Walls of Old San Juan, protected strategically and militarily important Puerto Rico, or La Llave de las Indias, from invasion by competing world powers during the Age of Discovery and Sail. It was designated a World Heritage Site by UNESCO in 1983.