John Montagu, 2nd Duke of Montagu (1689 - 1749), in 1745 raised a cavalry regiment known as Montagu's Carabineers, which, however, was disbanded after Culloden.

He was made a KG in 1719, and was a fellow of the Royal Society. As neither of his two sons survived him the title became extinct at his death in 1749, but in 1730 his daughter Mary married George Brudenell, 4th Earl of Cardigan (1712-1790), who on his father-in-law's death assumed the name and arms of Montagu, and in 1766 was created duke of Montagu.

On his death, in 1790, this second dukedom of Montagu also became extinct; his only son, who was, created Baron Montagu of Boughton, having predeceased him. His daughter Elizabeth married Henry, 2nd duke of Buccleuch, who thus acquired all the unentailed property of the dukes of Montagu, the entailed portion passing to the earls of Cardigan.

This article incorporates text from the public domain 1911 Encyclopædia Britannica.