Ranulf died in 1232 without a male heir, and his titles, lands and castles passed to his sisters. Following the death of Henry of Grosmont, 1st Duke of Lancaster in 1361 Bolingbroke passed through marriage into the ownership of John of Gaunt. His wife Blanche of Lancaster, daughter of Henry of Grosmont, was born at the castle in 1342. John and Blanche's son, Henry (the future Henry IV), was also born at Bolingbroke Castle in 1367 and consequently was known as "Henry Bolingbroke" before he became king in 1399.