The eldest son of Henry IV became king in 1413
[DOC] [TLE] KING HENRY IV OF ENGLAND (1367-1413) [Henry Bolingbroke ... [PAR] Apr 16, 2007 ... HENRY IV, King of England, son of John of Gaunt, by Blanche, daughter ... 
Parliament formally accepted him, and thus Henry became king, "not... [DOC] [TLE] Henry IV - Britannia.com [PAR] Henry IV.