1399:

King Richard II of England Abdicates

Maneuvered into abdicating by his cousin Henry Bolingbroke, who succeeded him as Henry IV, Richard was at first imprisoned and then later died "of uncertain causes" sometime the following February.

1547:

Miguel de Cervantes

Creator of Don Quixote, Miguel de Cervantes Saavedra is generally considered the most significant figure in Spanish literature.