Isabel of Beaumont

Isabel de Beaumont, Duchess of Lancaster, was an English-French noblewoman born around 1318. She was the youngest daughter of Henry de Beaumont, Earl of Buchan, and Alice Comyn, Countess of Buchan. Her family included her brother John de Beaumont, 2nd Lord Beaumont, and her paternal grandparents were Louis of Brienne and Agnes, Viscountess de Beaumont.

In 1330, Isabel married Henry of Grosmont, 1st Duke of Lancaster, although the marriage was not consummated immediately due to her young age. As the senior lady of the Lancaster household, she accompanied her husband on diplomatic missions to the continent, including trips to the Low Countries and Gascony. In 1351, she became the first woman in England to hold the title of Duchess of Lancaster.

Isabel died of the plague in 1361 at Leicester Castle and was buried in Newark Abbey, Leicester. Her daughters inherited their father's estates, continuing the lineage through the Royal House of Lancaster.