His maternal grandparents were Elizabeth Woolley and Robert Bristow, MP for Winchelsea.
[4] Hobart represented the constituencies of St Ives and Bere Alston in the House of Commons from 1754 to 1761 and 1761 to 1780, respectively.
He was secretary to the embassy in St Petersburg in 1762, his half-brother John Hobart, 2nd Earl of Buckinghamshire being then ambassador.
On 29 April 1797, he was commissioned colonel of the 3rd Regiment of Lincolnshire Militia (South Lincolnshire Supplementary Militia), becoming a colonel in the regular army when his regiment was embodied on 12 January 1799.
[6] They had eight children:[2] Lord Buckinghamshire died on 14 November 1804 and was succeeded by his son, Robert, who had already entered the House of Lords in 1798 by a writ of acceleration as Baron Hobart.