Naval Captain.

Younger brother of the famous John Montagu, fourth earl of sandwich, first lord of the admiralty.

Lieutenant on Defiance in West Indies, 1740; at attack on Cartagena, 1741; to the Launceston; command of sloop Mercury, 1744;

At night off Antigua ordered sentry to fire on small boat that would not respond to challenge, a wounded black man was bought on board who bled to death, 1744; the surgeon aboard the Mercury was court-martialed and dismissed for incompetence, but the fleet commander (Knowles) believed that Montagu was to blame and had him returned under arrest to England; Knowles refused to turn Montagu over to Antigua civil court or to court-martial Montagu (despite Montagu's efforts to obtain his own court martial!); after 7 months under arrest was placed in charge of the mail ship Mermaid, 1745; sued Knowles in civil court and won, received only 10 guineas, 1752;

Parliament representing Huntingdon county (he could not have been a very attentive representative!), 1745; command of Prince Edward, 1745; of Bristol (50 guns), 1746; under Anson against the French, described as `extremely brilliant' in close action against the Invincible (74 guns), and the Diamant (66 guns), 1747; to another English commander of a larger ship requesting that he move aside:

`Run foul of me and be damned; neither you nor any man in the world shall come between me and my enemy.'

Confined briefly by the admiral at the request of the governor of Madeira for threatening the life of the captain of an East Indiaman, 1747;

Known in the navy as an eccentric, nick-named `Mad Montagu'.

Sources:
[DNB].

http://www.montaguemillennium.com/familyresearch/h_1757_william.htm