John de Montacute, 1st Baron Montacute 14th-century English nobleman and loyal servant of King Edward III of England (1330–1390) Parents William Montagu, 1st Earl of Salisbury Catherine Montagu, Countess of Salisbury Children Ellen|Alianore de Montagu John Montacute, 3rd Earl of Salisbury Siblings Philippa de Montagu William de Montacute, 2nd Earl of Salisbury Lady Elizabeth Montagu Lady Sibyl Montagu Partners Margaret de Monthermer Margaret de Monthermer, 3rd Baroness Monthermer