earl of Cornwall Richard, 1209–72, second son of King John of England and brother of Henry III. In 1227, following an expedition to Gascony and Poitou, Richard forced Henry to grant him the land and wealth he regarded as his right, as well as the title of earl of Cornwall. He improved his position further by his marriage (1231) to Isabella, daughter of William Marshall, 1st earl of Pembroke. He went on a crusade in 1240 and concluded (1241) a truce with the sultan of Egypt. On Henry's expedition to Poitou in 1242, Richard was barely able to save his brother from complete military disaster. In the 1230s, Richard had often associated himself with the baronial opposition to Henry. However, after his marriage (Isabella having died) to the queen's sister in 1243, he became a faithful supporter of the king and his most sensible adviser. He financed the reform of the coinage in 1247, adding greatly to his already considerable wealth, and acted as regent when Henry was out of the country. Richard refused (1252) Pope Innocent IV's offer of the Sicilian crown (which Henry later accepted for his son Edmund), but in 1257 he had himself elected king of the Romans (i.e., emperor-elect of the Holy Roman Empire). Richard was crowned at Aachen and made three visits to Germany, but was never more than nominal ruler there. When the Barons' War broke out in earnest, Richard was one of Henry's chief supporters. He was captured at the battle of Lewes (1264) and held prisoner until after the battle of Evesham (1265). In the settlement after the war he advised moderation against the rebels.

See biographies by N. Denham-Young (1947) and T. W. E. Roche (1966).