Born in London and entered the ship Britannia
for his initial naval training; between 1879 and 1882, he accompanied the princes Albert Victor
on their training cruise around the world, developing a strong friendship with the latter; in 1901, he became second in command of the liner Ophir
, and then received a promotion to captain; Wemyss was appointed commodore of the naval barracks at Devonport after completing the necessary sea time for promotion to flag rank, and promoted rear-admiral in 1910; after a period spent on half pay, at the outbreak of war, he was sent as base commander at Lemnos in the Aegean, to prepare for the upcoming assault on the Dardanelles; Wemyss went on to play an active role in the rest of this campaign; he replaced John Rushworth Jellicoe
as first sea lord in 1917; by the end of the war, his relationship with Admiral Beatty
, commander-in-chief of the Grand Fleet, was breaking down and becoming problematic; having been excluded from the 1919 victory honours list, Wemyss resigned his post later that year; he was, however, at that point promoted to admiral of the fleet and created Baron Wester Wemyss; later, most of his time was spent in France, although he did hold a number of directorships and presidency of the Institution of Naval Architects in England; he died in Cannes in 1933.