Shortly after Alastair’s birth, George V changed the name of the British Monarchy from the House of Saxe-Coburg and Gotha to the House of Windsor, relinquishing all German titles of the family who were British subjects. The First World War had broken out not long after Alastair’s birth and anti-German feelings were running high. Furthermore, George V also restricted the royal titles of Prince or Princess and the style of Royal Highness to the children of the sovereign, the children of the sovereign’s sons, and the eldest living son of the eldest son of the Prince of Wales. The new rules also stated the grandchildren of the sons of a monarch would bear the style and title of the children of dukes. As a grandson of Arthur, Duke of Connaught, the third son of Queen Victoria, Alastair was thus excluded from being a prince.
After the restructuring of the royal family, Alastair received the courtesy title of Earl of Macduff which was his mother’s secondary peerage from the dukedom of Fife. After attending Sandhurst, Alastair received a commission as a second lieutenant in the Royal Scots Greys (2nd Dragoons) which was based in Egypt. In 1939, Alastair was promoted to lieutenant and assigned to Ottawa as aide-de-camp to The Earl of Athlone, then Governor General of Canada, who has succeeded Alastair’s grandfather.
Alastair succeeded his grandfather as Duke of Connaught in January 1942 but he would have the title for fourteen months before his untimely death on 26 April 1943. While in Ottawa, Alastair apparently fell out of a window while intoxicated and died of hypothermia overnight, although the cause of death was concealed and reported to the press as natural causes. Alastair’s ashes were interred at St. Ninian’s Chapel, Braemar, Scotland.