Isabel of Beaumont

Isabel of Beaumont (c. 1318–1361), youngest daughter of Henry de Beaumont, Earl of Buchan, married Henry of Grosmont in 1330. She accompanied him on embassies, and when he was made Duke of Lancaster in 1351 she became the first Englishwoman to bear the title of duchess.

Her daughters Maud and Blanche married William V of Hainaut and John of Gaunt respectively, making her grandmother of Henry IV. She died of the plague at Leicester Castle in 1361, the same year as her husband.