Henry the Navigator leads Portuguese forces to victory over the Marinids at the Conquest of Ceuta.

Prince Henry of Portugal, Duke of Viseu, better known as Prince Henry the Navigator, was a Portuguese prince and a central figure in the early days of the Portuguese Empire and in the 15th-century European maritime exploration. Through his administrative direction, he is regarded as the main initiator of what would be known as the Age of Discovery. Henry was the fourth child of King John I of Portugal, who founded the House of Aviz.

The Portuguese conquest of Ceuta took place on 21 August 1415, between Portuguese forces under the command of King John I of Portugal and the Marinid sultanate at the city of Ceuta. The city's defenses fell under Portuguese control after a carefully prepared attack, and the successful capture of the city marked the beginning of the Portuguese Empire. Ceuta remained under Portuguese control until being transferred to Spain in 1668.

August 21 is the 233rd day of the year in the Gregorian calendar; 132 days remain until the end of the year.