Ireton was a lawyer, diplomat and soldier and a leading figure in the Parliamentarian army.
Henry Ireton was born in 1611 in Nottinghamshire into a family of minor gentry. He studied at Cambridge University and in 1630, when the English Civil War began he raised a troop of cavalry and fought for the Parliamentarians at the battles of Edgehill (1642) and Gainsborough (1643). He then served as quartermaster-general to the Earl of Manchester in Yorkshire in the Marston Moor campaign of summer 1644, and at Newbury in October.
The poor performance of the Parliamentarian forces at Newbury led, in 1645, to the creation of the New Model Army, a single force under Sir Thomas Fairfax. As the summer's campaigning began Fairfax demanded his old comrade-in-arms, Oliver Cromwell, as lieutenant general of horse. On the night before the Battle of Naseby (June 1645) Ireton led a raid on the Royalist camp and took a number of prisoners. Cromwell had him appointed night commissary-general and put in command of the cavalry on the left wing of the Parliamentarian army. He fought bravely but was wounded and captured, escaping after the Parliamentarian victory.
In 1646, the year of Charles I's surrender, Ireton married Bridget Cromwell, Oliver's 22-year-old daughter. The victorious army then became involved in arguments with parliament, in part about lack of pay. Ireton emerged as one of the ablest politicians among the army leadership. He played an important part in upholding his men's interests, but declined to support their more extreme political ideas, proposing a constitutional monarchy. He was involved with negotiations with the king, but after Charles fled to the Isle of Wight, Ireton became convinced that there was no point negotiating further. He was involved in the organisation of the king's trial, and was one of those who signed his death warrant.
Ireton accompanied Cromwell on his campaign in Ireland in 1649 - taking part in the storming of Drogheda and Wexford - and assumed command when Cromwell returned to England in May 1650. He encouraged English settlers to come to Ireland and invested heavily in land there himself. He recommended a more lenient approach towards the Irish, but his advice was ignored. Ireton died on 26 November 1651 while he was directing the siege of Limerick. After the restoration of the monarchy, Ireton's body was exhumed and displayed as a regicide.