Lambert, John (1619-83). Lambert was a good cavalry commander in the first civil war, and a leading general in the second, serving with Cromwell at Preston. He added to his military reputation at Dunbar in 1650 and at Worcester in 1651. He was largely responsible for the Instrument of Government setting up the Protectorate in 1653, and was widely tipped as Cromwell's successor. In 1657 however he went too far in opposing the Humble Petition and Advice and was stripped of his military and civil appointments. Triumphantly reinstated when the army overturned Richard Cromwell in 1659, he looked like a Monck in the making. But his position collapsed speedily. When Monck in Scotland threatened to intervene on the Rump's behalf, Lambert marched north to face him, but his troops melted away. He was captured and put in the Tower. Lambert spent the remaining 23 years of his life in captivity, mainly in the Channel Islands.

1619–83, English parliamentary general. He fought in the first civil war (1642–46) and assisted Henry Ireton in drawing up the Heads of the Proposals in 1647. In 1648 he commanded the Army of the North against the Scots in the second civil war and later took part in the Scottish campaigns of 1650–51 and the defeat of Charles II at Worcester. He played a leading role in drafting the Instrument of Government (1653), by which Oliver Cromwell became protector, but broke with Cromwell over the latter's acceptance of the Humble Petition and Advice. At the fall of Richard Cromwell (1659) Lambert defeated a royalist uprising in Cheshire and assisted in dissolving the Rump Parliament. When Gen. George Monck marched south to restore Parliament, Lambert attempted to join him, but his army deserted him. After the Restoration (1660), he was tried for treason and banished to the island of Guernsey.