The daughter of Humphrey de Bohun, Earl of Hereford, she was a great heiress, and her elder sister, Eleanor, became the wife of Thomas of Woodstock. Mary married Henry, then known as Bolingbroke and nowhere in the line of succession to the throne, in 1380 or 1381. It was at Monmouth, one of her father's possessions, that she gave birth to her first two sons, Edward (who died in infancy) and Henry. Three more sons and two daughters were born in the years up to 1394. May died giving birth to the last child, Philippa, later the wife of Eric of Pomerania.