On 5 June 1886 he was commissioned as a
Lieutenant in the part-time
4th (Northampton and Rutland Militia) Battalion, Northamptonshire Regiment. His progress was slow: at the following year's annual training the inspecting officer noted: 'Lord Loughborough must become efficient by next training'. However he was able to obtain a Regular Army commission as a
2nd Lieutenant in the prestigious
Royal Horse Guards on 28 June 1890. However, on the death of his father a few weeks later he immediately gave up this career, and instead came a Lieutenant in the part-time
1st Fifeshire Light Horse Volunteers on 18 October 1890. Lord Rosslyn succeeded his father in the earldom on 6 September 1890, inheriting the family seat,
Rosslyn Castle in
Midlothian, Scotland and
Rosslyn Chapel,
collieries at
Dysart, a luxury steam yacht, and assets of £50,000. His mother, the dowager Countess of Rosslyn, survived his father by over 40 years before her death at
Regent's Park, London, in December 1933. He reached the rank of
Captain in the Fifeshire Light Horse, but resigned on 24 November 1897 after his bankruptcy. However he joined
Alexander Thorneycroft's Mounted Infantry during the
Second Boer War where he was taken prisoner twice, which he wrote about in his book
Twice Captured. Lord Rosslyn was also war correspondent for the
Daily Mail in 1900. In 1904, he was Secretary to the
Secretary of State for Scotland and from 1915 to 1917, he was Major in the
King's Royal Rifle Corps. which led to the family silver, gold and silver plate being sold at a three-day auction in
Edinburgh. In 1903, he was in Court for refusing to pay a $150 draft. In 1908, Rosslyn and
Sir Hiram Maxim were in the news for a gambling duel in Monte Carlo to "break the bank". ==Personal life==