Mar 22 Thomas of Lancaster, 1st Duke of Clarence, second son of Henry IV of England (killed in battle) (b. 1388) died in the year 1421.
May 26 Mohammed I, sultan of Turkey (1413-21), dies in the year 1421.
Jun 21 In the year 1421 death of jean Le Maingre, Marshal of France (b. 1366)