He inherited the entailed property from the 4th Marquess, including Ragley Hall, whilst the unentailed property went to his second cousin's illegitimate son Richard Wallace, including what became the Wallace Collection.

[2] Seymour joined the Scots Fusilier Guards as a lieutenant in July 1827, rising to the rank of general in 1876 and retiring in 1881.

They had ten children: His brother-in-law was Prince Victor of Hohenlohe-Langenburg, a nephew of Queen Victoria and a famous sculptor, who had married his sister Laura Williamina Seymour (later Princess Victor of Hohenlohe-Langenburg).

Lord Hertford died on 25 January 1884, aged 71, from injuries following a fall from a horse at Ragley Hall.

The Dowager Marchioness of Hertford died at Westcott, Surrey, on 24 June 1902, aged 86.