Almost nothing is known of his career prior to the beginning of the
First English Civil War in August 1642, when he raised a company for the
Manchester garrison. In December, he was captured in a skirmish near
Westhoughton, Lancashire but quickly released. The Venables family had long-standing connections to the Breretons, one of the most powerful families in Cheshire, and for the rest of the war he served under
Sir William Brereton, the senior local
Parliamentarian. Despite lacking military experience, Brereton proved an energetic and resolute commander, winning minor victories in March 1643 at
Middlewich and
Hopton Heath. Brereton established his headquarters at
Nantwich and quickly attained superiority over
Arthur Capell, Royalist commander in
Shropshire, Cheshire, and
North Wales. From August to September 1643, Venables was based at
Cholmondeley, which he used as a base for attacking nearby Royalist garrisons. These supported the
blockade of Chester, a town essential for funnelling men and material from Royalist areas in Ireland and North Wales. Their success led to Capell's replacement by
Lord Byron in October 1643. Byron assembled an army of over 5,000, including many veterans from the
war in Ireland, and defeated the Parliamentarians at the
Second Battle of Middlewich in December. Brereton appealed to Sir
Thomas Fairfax for support, and their combined force routed the Royalists at
Nantwich in January 1644. Having lost over 1,500 men and most of his artillery, Byron retreated into Chester, and Venables spent much of the next two years as governor of
Tarvin. When Chester finally surrendered in February 1646, Brereton recommended him as governor, but instead the position went to Irishman
Michael Jones. Now a
lieutenant colonel, Venables spent the next few months reducing Royalist garrisons in North Wales before the war ended in June. Despite victory, the cost of the war, a poor 1646 harvest, and a recurrence of the plague left Parliament unable to pay their soldiers. In summer 1647, the garrison of Nantwich mutinied; Venables restored order, and was made governor of
Liverpool in January 1648, a position he held during the
Second English Civil War. Promoted
colonel in 1649, he raised a regiment of Cheshire veterans sent to reinforce Michael Jones, newly appointed Parliamentarian Governor of
Dublin. They arrived in time for the
Battle of Rathmines on 2 August, a decisive victory over a Royalist/
Confederate force under the
Marquess of Ormond. On 15 August,
Oliver Cromwell arrived with an expeditionary force of 12,000 to begin the
conquest of Ireland, and Venables took part in the
storming of Drogheda. He then joined forces with
Sir Charles Coote in
Ulster, and supported by local
Presbyterian militia, their combined forces captured
Belfast in late September, then won a decisive victory at
Lisnagarvey in December 1649. After another victory at
Scariffhollis in June 1650,
Charlemont, the last Confederate stronghold in Ulster, surrendered in August 1650. Although sporadic skirmishing continued until 1653, the Confederacy dissolved in 1651. Venables spent the next two years fighting an often brutal counter insurgency war in north
Connaught and south-west Ulster; his troops were always in arrears with their pay, and on several occasions he and Jones resorted to confiscating taxes collected for Dublin. In 1653, he helped implement the
Act for the Settlement of Ireland 1652, while resisting attempts to impose
Presbyterianism in Ulster; like many in the New Model, he was a religious
Independent, who opposed any state-ordered church. ==The Western Design==