St Maur served as a captain in theRoyal Horse Guards.[1] His father died in 1855. St Maur succeeded his elder brothersEdward (1804–1885), andArchibald (1810–1891), both of whom died without living male heirs, in the dukedom.[3]
On 17 May 1845, he married Horatia Isabella Harriet Morier (1819–1915), daughter of diplomatJohn Philip Morier and Horatia Maria Frances Seymour (eldest daughter ofLord Hugh Seymour, himself the youngest son of the1st Marquess of Hertford).[4][5] Together, they had four sons:[2]
Lord Ernest St Maur (1847–1922), who married Dora Constable, daughter of the Rev. John Constable, in 1907.[2]
Lord Edward St Maur (1849–1920), a Lieutenant in the60th Rifles; he married Lilian Stanhope, daughter of John Stanhope, in 1879.[2]
He died suddenly while visiting theWells, Somerset home of Charles Clement Tudway (the son of MPRobert Tudway). He experienced indigestion followed by an apparent heart attack.[1]
