[4] In June 1887, aged seventeen, Hore-Ruthven was commissioned as a second lieutenant into the 3rd (Militia) Battalion of the Argyll and Sutherland Highlanders.

[11] Ruthven later served in the First World War, becoming a GSO1 in succession to Lieutenant Colonel William Thwaites in June 1915.

[2] After the war he became commander of the Bangalore Brigade in India and was promoted to substantive major general in January 1923.

His eldest daughter, Bridget Monckton, 11th Lady Ruthven of Freeland, succeeded him in his more senior title as it was in the Peerage of Scotland and thus may be inherited by female descendants.

It has been held since 1994 by his great-grandson George Howard, 13th Earl of Carlisle, grandson of Bridget Monckton, 11th Lady Ruthven of Freeland.