Duke of Montagu
The title of Duke of Montagu has been created twice for members of the noble House of Montagu. It was first created in the Peerage of England in 1705 for Ralph Montagu, 3rd Baron Montagu of Boughton, with the subsidiary title Marquess of Monthermer, but became extinct in 1749. The first Duke had been created Earl of Montagu and Viscount Monthermer in 1689. The Dukedom was then recreated in the Peerage of Great Britain in 1766 for the late Duke's son-in-law, George Montagu, 4th Earl of Cardigan, with the subsidiary title Marquess of Monthermer. On his death in 1790 the dukedom and marquessate became extinct, and the earldom passed to his brother, James Brudenell, 5th Earl of Cardigan. The dukedom is named for the ancient Anglo-Norman family rather than any place.Earls of Montagu (1689)
- Ralph Montagu, 3rd Baron Montagu of Boughton, 1st Earl of Montagu
Dukes of Montagu, first Creation (1705)
- Ralph Montagu, 1st Duke of Montagu was a courtier and diplomat
- John Montagu, 2nd Duke of Montagu, only son of the 1st Duke, died without male issue
Dukes of Montagu, second Creation (1766)
- George Montagu, 1st Duke of Montagu, son-in-law of the late 2nd Duke
- *John Montagu, Marquess of Monthermer, only son of the 1st Duke, predeceased his father unmarried
