Duke of Lancaster, third son of Edward III., born at Ghent, who in 1362 succeeded to the estates of his father-in-law, the Duke of Lancaster; having in 1372 married, as his second wife, the daughter of the king of Castile, he made an unsuccessful attempt to seize the Castilian throne; in the later years of Edward III.'s reign he took an active part in public affairs, and by his opposition to the national party and overbearing conduct towards the Commons made himself obnoxious to the people; for selfish motives he for a time supported Wycliffe, but in 1381 the Peasant Revolt drove him into Scotland; in 1386 he made another ineffectual attempt to gain the crown of Castile; in his later years he was engaged in various embassies in France (1339-1399).