The Lords Appellant were the organised opposition to the rule of King Richard II of England which emerged during the 1380s, so called because they were appealing to the King for good government. The Lords were led by Thomas of Woodstock the Duke of Gloucester (youngest son of Edward III and King Richard's uncle), Richard Fitzalan the Earl of Arundel, and Thomas de Beauchamp the Earl of Warwick.

In 1387 they defeated King Richard's forces at Radcot Bridge outside Oxford and in 1388 they impeached Richard's Chancellor the Earl of Suffolk, executed other of his close advisors and exiled Robert de Vere, Richard's favorite.

In 1389 John of Gaunt returned from Spain and Richard ruled in apparent harmony with Gaunt and the other Lords Appellant until 1397 when Richard again asserted his authority, executing Arundel, banishing Warwick, while Gloucester died in captivity.