Prince Alexander passed a qualifying examination to become service cadet in the Royal Navy in March 1902, and subsequently joined the cadet training ship HMS Britannia at Dartmouth on 8 May 1902. He served in the Royal Navy from 1902 to 1908 and in 1910, became one of the earliest members of The Castaways' Club, an exclusive dining club for Naval officers who resigned while still junior but who wished to keep in touch with their former service. Several of his Mountbatten cousins were also subsequently members, including the Marquess of Milford Haven and Duke of Edinburgh. In 1909, he joined the British Army, being appointed Second Lieutenant in the Grenadier Guards on 4 August 1909. He was confirmed in the rank on 22 November 1911, and was promoted to Lieutenant on 15 August 1913. He was seconded to the staff to act as an extra aide-de-camp on 10 April 1915 and promoted to captain the same year. On 1 June 1917, he was authorised to wear the insignia of the Russian Order of St Vladimir, fourth class with Swords, awarded "for distinguished service to the Allied cause." He resigned his commission on 19 June 1919 and was placed on the General Reserve of Officers, ranking as a Captain with seniority of 15 July 1915. He held several other foreign orders and decorations: Grand Cross and Collar of Order of Charles III, Order of Leopold, with swords, Order of Saint Alexander Nevsky, Order of Naval Merit, fourth class, Order of the Nile, Order of the Crown, and Croix de guerre, with palms. During World War II, despite being in his mid-fifties, the Marquess joined the Royal Air Force and was commissioned an acting pilot officer on 6 June 1941. On 6 August, he was regraded as a pilot officer. He was confirmed in his rank on 6 June 1942 and was promoted to flying officer on 6 August 1942. During the war, he was a staff officer attached to Air Chief MarshalSir Trafford Leigh-Mallory. He relinquished his commission on 21 May 1945, retaining the rank of flight lieutenant.
Marquess of Carisbrooke
Anti-German feeling during the First World War led George V to change the name of the Royal House in July 1917 from the House of Saxe-Coburg-Gotha to the House of Windsor. He also relinquished, on behalf of his various relatives who were British subjects, the use of all German titles and styles. The Battenberg family relinquished their titles of Prince and Princess of Battenberg and the styles of Highness and Serene Highness. Under royal warrant, they instead took the surname Mountbatten, an Anglicised form of Battenberg. As such, Prince Alexander became Sir Alexander Mountbatten. On 7 November 1917, he was created Marquess of Carisbrooke, Earl of Berkhamsted and Viscount Launceston. In the 1930s, author E.F. Benson dedicated two of his famous novels, Mapp and Lucia and Lucia's Progress, to the Marquess of Carisbrooke.
According to the published diaries of Cecil Beaton, in his later years Lord Carisbrooke had a longtime male lover, Simon Fleet. More is written about Lord Carisbrooke and his wife in the published diaries of James Lees-Milne.
Later career
Lord Carisbrooke, who received no state allowance, became the first member of the British royal family to work in the commercial sector. He began his career working as an entry-level clerk in the offices of Lazard Brothers bankers. He later worked for a company that oversaw housing estates, and before long he took control of social work for the tenants. Later he became a director of Lever Brothers and several other prominent corporations.
Death
Lord Carisbrooke, died in 1960, aged 73, at Kensington Palace, and his ashes were buried within the Battenberg Chapel in St. Mildred's Church, Whippingham on the Isle of Wight. The title Marquess of Carisbrooke became extinct upon his death.
Titles, styles and honours
23 November 1886 – 13 December 1886: His Serene Highness Prince Alexander of Battenberg
13 December 1886 – 1910: His Highness Prince Alexander of Battenberg
1910–1917: His Highness Prince Alexander of Battenberg
1917: Sir Alexander Mountbatten
1917–1960: The Most Hon The Marquess of Carisbrooke