Sixteen-year-old Otto III is crowned Holy Roman Emperor.

Otto III was the Holy Roman emperor and King of Italy from 996 until his death in 1002. A member of the Ottonian dynasty, Otto III was the only son of Emperor Otto II and his wife Theophanu.

The Holy Roman Emperor, originally and officially the Emperor of the Romans during the Middle Ages, and also known as the Roman-German Emperor since the early modern period, was the ruler and head of state of the Holy Roman Empire. The title was held in conjunction with the title of King of Italy from the 8th to the 16th century, and, almost without interruption, with the title of King of Germany throughout the 12th to 18th centuries.

May 21 is the 141st day of the year in the Gregorian calendar; 224 days remain until the end of the year.