Alexander Montagu, 10th Duke of Manchester

Commander Alexander George Francis Drogo Montagu, 10th Duke of Manchester, OBE, RN (2 October 1902 – 23 November 1977) was a Royal Navy officer and British hereditary peer. From birth until February 1947, he was known by the courtesy title of Viscount Mandeville.

Early life Born at Tandragee Castle in County Armagh, Ulster, in the north of Ireland on 2 October 1902, Lord Mandeville was the son of the 9th Duke of Manchester by his marriage to Helena Zimmerman, the only child of Eugene Zimmerman, of Cincinnati, Ohio, United States, a railway president and major stockholder in Standard Oil. The wedding in November 1900 was kept secret from both families, and at first the Duke's mother did not believe reports of it. Queen Alexandra stood sponsor at his christening in the Chapel Royal (St. James's Palace) on 17 December 1902.

In 1931, his parents were divorced, when his father was reported to be planning to marry an actress. In 1937, Helena Manchester married secondly the 10th Earl of Kintore.

Mandeville was educated at the Royal Naval College, Osborne, and the Royal Naval College, Dartmouth. He succeeded to the Dukedom of Manchester on his father's death in February 1947. then to William Willard Crocker, a son of William Henry Crocker and grandson of Charles Crocker.

At the time of his death in 1977, he was still listed in Who's Who as living at Kapsirowa, Hoey's Bridge, Kenya, but he died in London, after running through most of his inherited wealth.

His elder son, Sidney Arthur Robin George Drogo Montagu, succeeded him as 11th Duke of Manchester. He died without issue, so his brother, Angus Charles Drogo Montagu, became the 12th Duke.