Edmund, king of Sicily and earl of Lancaster (1245-1296), was the second son of Henry III. of England by Eleanor of Provence. At ten years of age Edmund was invested by Pope Alexander IV. with the kingdom of Sicily (April 1255); the pecuniary obligations which Henry III. undertook on his son’s behalf were not the least among the causes which led to the Provisions of Oxford and the Barons’ War. Alexander annulled his grant in 1258, but still pressed Henry for the discharge of unpaid arrears of subsidies. In 1265, after Montfort’s fall, Edmund received the earldom of Leicester, and two years later was created earl of Lancaster. He joined the crusade of his elder brother, the Lord Edward (1271-1272); and Edward, on his accession, found in Edmund a loyal supporter. In 1275, two years after the death of his first wife, Aveline de Fortibus, Edmund married Blanche of Artois, the widow of Henry III. of Navarre and Champagne. Although the county of Champagne had descended to his wife’s infant daughter, Joan, Edmund assumed the title “Count Palatine of Champagne and Brie,” and is described in the English patent rolls as earl of Lancaster and Champagne. Until 1284 he held, in his wife’s right, the custody of Champagne. This he was compelled to renounce upon the marriage of Joan to Philip the Fair, the heir to the crown of France. But he retained the possession of his wife’s dowerlands in Champagne, and is described in an official document of Champagne so late as the year 1287, as “the Count Edmund.” He was employed by his brother as a mediator with Philip the Fair in 1293-1294. When Philip’s court pronounced that the king of England had forfeited Gascony, Edmund renounced his homage to Philip and withdrew with his wife to England. He was appointed lieutenant of Gascony in 1296, but died in the same year, leaving a son Thomas to succeed him in his English possessions.
See “Edmund, Earl of Lancaster,” by W.E. Rhodes, in the English Historical Review, vol. x. pp. 19, 209.