The title of Earl of Lancaster was created in the Peerage of England in 1267. It was succeeded by the title Duke of Lancaster in 1351, which expired in 1361. (The most recent creation of the ducal title merged with the Crown in 1413.) King Henry III of England created the Earldom of Lancasterfrom which the royal house of Henry IV was namedfor his second son, Edmund Crouchback, in 1267. Edmund had already been created Earl of Leicester in 1265 and following the Second Barons' War and the death and attainder of the king's rebellious brother-in-law Simon de Montfort, 6th Earl of Leicester in 1265, the latter's lands, including most notably Kenilworth Castle in Warwickshire, had been awarded to him. When Edmund's son Thomas, 2nd Earl of Lancaster, inherited the estates and title of his father-in-law Henry de Lacy, 3rd Earl of Lincoln, he became at a stroke the most powerful nobleman in England, with lands throughout the kingdom and the ability to raise vast private armies to wield power at national and local levels. This brought himand his younger brother Henry, 3rd Earl of Lancasterinto conflict with their first cousin King Edward II, leading to Thomas's execution. Henry inherited Thomas's titles and he and his son Henry of Grosmont, 1st Duke of Lancaster, gave loyal service to Edward's son King Edward III. History Creation After the supporters of Henry III of England suppressed opposition from the English nobility in the Second Barons' War, Henry granted to his second son Edmund Crouchback the titles and possessions forfeited by attainder of the barons' leader, Simon de Montfort, 6th Earl of Leicester, including the Earldom of Leicester, on 26 October 1265. Later grants included the first Earldom of Lancaster on 30 June 1267 and that of Earl Ferrers in 1301. Edmund was also Count of Champagne and Brie from 1276 by right of his wife. Henry IV of England would later use his descent from Edmund to legitimise his claim to the throne, even making the spurious claim that Edmund was the elder son of Henry but had been passed over as king because of his deformity. Edmund's second marriage to Blanche of Artois, the widow of the King of Navarre, placed him at the centre of the European aristocracy. Blanche's daughter Joan I of Navarre was queen regnant of Navarre and through her marriage to Philip IV of France was queen