cousin the Earl of Manchester and served under him in the Eastern Association. He raised a regiment of infantry which during the 1644 campaign fought at Marston Moor, the Siege of York and Second Newbury. Despite his family relationship, Montagu supported those in Parliament who expressed dissatisfaction with the conduct of the war by Manchester and the Earl of Essex. This resulted in the creation of the New Model Army in February 1645 and the passing of the Self-denying Ordinance, requiring any of those holding military commissions to resign from Parliament. As members of the House of Lords, Manchester and Essex were automatically removed, since unlike MPs they could not resign their titles. Montagu's regiment was incorporated into the New Model, taking part in the June 1645 Battle of Naseby, followed by the capture of Bristol. In October, he resigned from the army as required by the Ordinance when was appointed MP for Huntingdonshire, a seat formerly held by his father who died in September 1644. Montagu played no part in the Second English Civil War and retired from Parliament after Pride's Purge in December 1648 to live quietly at home. He returned to politics in 1653 when his neighbour Oliver Cromwell nominated him to the Barebones Parliament as MP for Huntingdonshire, a seat formerly held by his father who died in September 1644. He was also appointed to the English Council of State, an office he held until it was dissolved in 1659, and was re-elected to the First Protectorate Parliament in 1654, then the Second Protectorate Parliament in 1656. During the Anglo-Spanish War (1654–1660), he was appointed joint General at Sea with Robert Blake, taking part in an expedition into the Mediterranean. This experience made him a leading advocate of establishing a British naval base in the region, an ambition realised with the acquisition of English Tangier in 1661. In February 1657, he was one of the so-called "New Cromwellians" who supported the Humble Petition and Advice, inviting Cromwell to declare himself king and advocating the re-establishment of a national church. The measure was opposed by army radicals including Charles Fleetwood and John Lambert and ultimately rejected. In June 1658 he commanded the naval squadron that blockaded Dunkirk and when Cromwell died in September, Montagu remained loyal to his son and appointed successor Richard Cromwell. During his brief and disastrous rule as Lord Protector, Montagu remained at sea