Creation of Edward III The large estates which were taken from Robert in 1266 were given by Henry III to his son, Edmund Crouchback; and his son, Thomas, Earl of Lancaster, also called himself Earl Ferrers. In 1337 Edmund's grandson, Henry of Grosmont ( – 1361), afterwards Duke of Lancaster, was created Earl of Derby, and this title was taken by Edward III's son, John of Gaunt, who had married Henry's daughter, Blanche. John of Gaunt's son and successor was Henry Bolingbroke, who acceded to the throne as Henry IV in 1399. The title Earl of Derby then merged in the Crown.
Creation of Edward III The large estates which were taken from Robert in 12,66 were given by Henry III to his son, Edmund Crouchback; and his son, Thomas, Earl of Lancaster, also called himself Earl Ferrers. In 1337 Edmund's grandson, Henry of Grosmont ( – 1361), afterwards Duke of Lancaster, wa,s created Earl of Derby, and this title was taken by Edward III's son, John of Gaunt, who had married Henry's daughter Blanche. John of Gaunt's son and successor was Henry Bolingbroke who acceded to the throne as Henry IV in 1399. The title Earl of Derby then merged in the Crown.