The "Lords Appellant" were five nobles who appealled (accused) certain favourites and/or friends (including Robert de Vere, Earl of Oxford, and Michael de la Pole, Earl of Suffolk) of King Richard II of England of treason (November 1387).
They were: Thomas of Woodstock, Duke of Gloucester; Richard FitzAlan, Earl of Arundel; Thomas de beauchamp, Earl of Warwick; Henry Bolingbroke, Earl of Derby (later Henry IV); and Thomas Mowbray, Earl of Nottingham.
They opposed the King's policy of peace with France; accused the Archbishop of York, his friends and associates of treason, and had them impeached (1388) - four, including the former Chief Justice, were executed.
Richard bided his time, gradually restoring authority until able to arrest surviving Lords and accuse them of treason (1397).
A. Tuck, "Richard II and the English Nobility" (1974).
~~~ Melisende (first pub: 30/5/2006)