House of York and Ireland

The Yorkists and Lancastrians were descended directly from Edward III. The first Duke of York was Edward's fifth son, Edmund Plantagenet; the first Duke of Lancaster was John of Gaunt, the fourth son of the same monarch. Richard II. succeeded his grandfather, Edward III., as the son of Edward the Black Prince, so famed in English chivalry. His arrogance and extravagance soon made him unpopular; and, during his absence in Ireland, the Duke of Lancaster, whom he had banished, and treated most unjustly, returned to England, and inaugurated the fatal quarrel. The King was obliged to return immediately, and committed the government of the country to his cousin, Roger de Mortimer, who was next in succession to the English crown, in right of his mother, Philippa, the only child of the Duke of Clarence, third son of Edward III. The death of this nobleman opened the way for the intrusion of the Lancastrians, the Duke of Lancaster having obtained the crown during the lifetime of Richard, to the exclusion of the rightful heir-apparent, Edmund, Earl of March, son to the late Viceroy.