Public life
Portland initially embarked on a military career and served as a lieutenant in the Coldstream Guards from 1877 to 1880, and then as lieutenant-colonel of the part-time Honourable Artillery Company from 1881 to 1889. He was honorary colonel of the 1st Lanarkshire Artillery Volunteers from 1884 to 1891, of the 4th (Royal Sherwood Foresters Militia) Battalion, Sherwood Foresters, from 1889 and its Special Reserve successor from 1908, and of the 7th (Robin Hood) Battalion, Sherwood Foresters (Volunteers, later Territorial Force) from 1898.
He sat on the Conservative benches in the House of Lords and held office as Master of the Horse under Lord Salisbury from 1886 to 1892 and from 1895 to 1902 and under Arthur Balfour from 1902 to 1905. In 1886, he was sworn of the Privy Council.
He was made a Knight Grand Cross of the Royal Victorian Order (GCVO) in 1896, and was a holder of the Royal Victorian Chain. In 1900 he was appointed a Knight Companion of the Garter, receiving the insignia in an investiture by Queen Victoria at Windsor Castle on 16 March 1900. He was appointed a Knight of Justice of the Order of the Hospital of St. John of Jerusalem in England (KStJ) in July 1901. He also held the Grand Cross of the Order of Charles III (Spain), 1st Class Order of St Sava (Serbia) the Grand Cordon of the Order of the Crown (Belgium), and the Grand Cross of the Order of St Stephen (Austria-Hungary).
The Portlands visited British India to attend the 1903 Delhi Durbar held in January 1903 to celebrated the succession of King Edward VII as Emperor of India.
He was Lord-Lieutenant of Caithness from 1889 to 1919, Lord Lieutenant of Nottinghamshire from 1898 to 1939, a Deputy Lieutenant of Ayrshire, and a trustee of the British Museum.
The Portlands received Archduke Franz Ferdinand of Austria at Welbeck Abbey for a week in 1913 when the heir to the Austro-Hungarian throne visited England. During the stay he took the Archduke shooting on the estate when, according to Portland's memoirs, Men, Women and Things:
"One of the loaders fell down. This caused both barrels of the gun he was carrying to be discharged, the shot passing within a few feet of the archduke and myself. I have often wondered whether the Great War might not have been averted, or at least postponed, had the archduke met his death there and not at Sarajevo the following year."
From 1937 to 1943 he was Chancellor of the Order of the Garter. At the coronation of King George VI Portland carried the crown of Queen Elizabeth, whose mother (the Countess of Strathmore and Kinghorne) was his cousin. It was at his estate in Langwell that the Sunderland Flying boat carrying Prince George, Duke of Kent (the King's youngest brother) crashed while en route to a RAF Base in Iceland.
