Arthur developed an interest in the army from a young age and he enrolled in the Royal Military College at Woolwich in 1866. After graduating two years later, Arthur was commissioned as a lieutenant in the Corps of Royal Engineers before transferring to the Royal Regiment of Artillery on 2 November 1868, and the Rifle Brigade in August 1869. Arthur had along and distinguished career in the army and he served in South Africa, Canada, Ireland, Egypt, and India.
On 13 March 1879, Arthur married Louise Margaret of Prussia, great-niece of Arthur’s godfather, Wilhelm I. The couple had three children: Margaret, born in January 1882; Arthur, born January 1883; and Patricia, born in March 1886. The children were all raised at Bagshot Park, in Surrey, and Clarence House, London. Margaret would eventually marry Crown Prince Gustaf Adolf of Sweden, however she would die before he ascended the throne.
Arthur continued his career in the army after his marriage and hoped to succeed Prince George, Duke of Cambridge, as Commander-in-chief of the British Army in 1895, however the post was denied to him and he was given command of the Aldershot District Command instead. In August 1899, the 6th Battalion, Rifles of the Canadian Non-Permanent Active Militia, asked Arthur to give his name to the regiment and act as its honorary colonel. After Arthur consented, the unit was renamed 6th Regiment, Duke of Connaught’s Own Rifles (DCORs) on 1 May 1900 and he was appointed colonel-in-chief in 1923.
On 1 October 1869, while serving in Canada, Arthur was given the title Chief of the Six Nations by the Iroquois of the Grand River Reserve in Ontario and the name Kavakoudge (meaning the sun flying from east to west under the guidance of the Great Spirit) which enabled him to sit in the tribe’s councils and vote on matters of tribe governance. The people of Canada were so impressed by Arthur, they were hoping he would be appointed as Governor General one day but they would have to wait until 1911.
In May 1874, Arthur was created Duke of Connaught and Strathearn, as well as Earl of Sussex, and he was in the line of succession for the dukedom of Saxe-Coburg and Gotha behind his older brother, Alfred, however he was displaced by the birth of Alfred’s only son, Affie. When young Affie died in 1899, Arthur renounced his rights to the succession so the dukedom could be passed to his nephew, Charles Edward, the posthumous son of Leopold, Duke of Albany.
On 6 March 1911, Arthur was finally appointed as Governor General of Canada by his nephew, George V, and he became the first Governor General of Canada who was a member of the British royal family when he was sworn in on 13 October 1911. Arthur and Louise traveled to Canada with their youngest daughter, Patricia, and together they traveled throughout the country while performing their official duties. The family stayed at Rideau Hall, the official residence of the viceroy, and they put a lot of effort into refurbishing the place.
When the First World War broke out, the Connaughts stayed in Canada and Arthur reiterated the need for military training and readiness for Canadian troops departing for war. The duke also visited hospitals and barracks to boost morale before the troops were sent abroad, however the Canadian Prime Minister, Robert Borden, resented the duke’s interference. While Arthur was rallying the troops, Louise supported the war effort by working for the Red Cross and was named Colonel-in-Chief of the Duchess of Connaught’s Own Irish Canadian Rangers battalion, one of the regiments in the Canadian Expeditionary Force. Patricia also lent her name and support to the raising of a new Canadian army regiment — Princess Patricia’s Canadian Light Infantry.
Arthur’s term as Governor General ended in 1916 and the duke returned to Britain where he continued his royal duties. After the death of his wife in 1917, Arthur withdrew from public life, however he returned to military life during the Second World War where he mentored new recruits. Arthur died on 16 January 1942 at Bagshot Park and was buried on 19 March 1942 in the Royal Burial Ground, Frogmore.