[9] Herbert was a member of the 2nd (Eton College) Buckinghamshire Rifle Volunteer Corps as early as 1905,[10] androm 1914 to 1919, served as a colonel in the First World War.

He was also a local director for Liverpool, London & Globe Insurance Co. Ltd.[6] Herbert became part of the Royal Household in 1928, with his appointment as a Gentleman Usher to King George V;[11][12][13] he took the place of Sir Lionel Cust, who had resigned.

[14] His appointment continued during the reigns of Edward VIII and George VI in turn;[15][16][17] in 1936 was named an aide-de-camp to the king,[18] and the following year a groom in waiting.

[24] George Herbert was himself bequeathed £40,000, along with a life interest in the Boyton Manor estate and £50,000 for its upkeep;[24] his responsibilities as executor also included attending to a locked tin deed box, which the will requested be "destroyed unopened by cremating".

[28][29] After £22,075 in taxes he bequeathed £500 to Salisbury Division Conservative Association, and £250 each to a butler, gardener, chauffeur, and keeper; the remaining £41,000 he left to his mother for life, and then to the family member living at Boyton.