The Ailesbury Mausoleum situated in the churchyard of St Mary's Church, Maulden, in Bedfordshire, is a Grade II listed structure built in 1656 by Thomas Bruce, 1st Earl of Elgin (1599–1663) (father by his 1st wife of Robert Bruce, 2nd Earl of Elgin, 1st Earl of Ailesbury (1626-1685)), of nearby Houghton House in the parish of Maulden, for the purpose of housing the coffin and "splendid monument"[1] of his second wife, Lady Diana Cecil (d. 1654), a daughter of William Cecil, 2nd Earl of Exeter and widow of Henry de Vere, 18th Earl of Oxford.[2] In the opinion of the architectural historian Sir Howard Colvin (1991)[3] it is one of the first two free-standing mausoleums ever built in England, together with the Cabell Mausoleum at Buckfastleigh in Devon.[4]