Background
Montagu was the sixth son of George Montagu of Horton, Northamptonshire, by his wife Elizabeth Irby, daughter of Sir Anthony Irby.
Montagu was the sixth son of George Montagu of Horton, Northamptonshire, by his wife Elizabeth Irby, daughter of Sir Anthony Irby.
As a politician, he sat in the House of Commons at various times between 1695 and 1713 and served as Solicitor General and Attorney General. He was entered at the Middle Temple, and called to the Barometer In 1705 he was committed by the House of Commons to the custody of the serjeant-at-arms for having in 1704 demanded a habeas corpus on behalf of the group of Aylesbury men, whom the house had committed to Newgate Prison for bringing actions against the returning officer
Montagu pleaded strongly against the privilege claimed by the Commons.
He remained in custody from 26 February to 14 March, when parliament was prorogued and afterwards dissolved. In April 1705 he was knighted at Cambridge, and was made a Queen's Counsel in November of the same year.
In the second parliament of Queen Anne, Montagu was returned for Carlisle. He became solicitor-general in 1707, and was attorney-general from 1708 to 1710, when the queen granted him a pension.
This pension was made the subject of a motion brought before the house in 1711, in which Colonel Gledhill represented it as intended to defray the expenses of Montagu"s election at Carlisle.
The charge was, however, disproved. As attorney-general Montagu opened the case in the House of Lords against Henry Sacheverell. He became serjeant-at-law on 26 October 1714, was made a Baron of the Exchequer on 22 November 1714, and was lord commissioner of the great seal (on the resignation of Lord Cowper) from 18 April to 12 May 1718, when Lord Parker became lord chancellor.
Montagu succeeded Sir Thomas Bury as chief baron of the exchequer in May 1722.
He died on 1 October 1723. Montagu married Tufton Wray, daughter of Sir William Wray, 1st Baronet, of Ashby in 1694.
Montagu"s brother was Charles Montagu, 1st Earl of Halifax.
In 1704 he successfully defended John Tutchin, indicted for a libel published in his periodical, The Observator, and two years later he was leading counsel in the prosecution of Beau Fielding for bigamy in marrying the Duchess of Cleveland.
1st Parliament of Great Britain. 2nd Parliament of Great Britain. 3rd Parliament of Great Britain]
In 1695 Montagu became Member of Parliament for Tregony, and for Beeralston in 1698, when he was also made chief justice of Ely.