The Harleys were one of the most powerful families in Herefordshire, while both Sir Robert and Lady Brilliana were
Presbyterians who used their influence to appoint
Nonconformist clergy to local positions. With this background, after leaving
Shrewsbury School in 1638, Harley entered
Magdalen Hall, Oxford, then a centre of
Puritan education. He left Oxford in 1640 to join his father in London, and attended
Lincoln's Inn from 1641 to 1642. , almost totally destroyed during the war When the
First English Civil War began in August 1642, the Harleys were among the minority of Herefordshire
landed gentry who supported
Parliament, and the county became a major source of
Royalist recruits. By 1643,
Parliamentarian forces controlled only a few strongholds in the area, including Brampton Bryan castle, where the garrison was commanded by Lady Brilliana. The local headquarters was
Gloucester, held throughout the conflict by
Edward Massey. During
William Waller's 1643 campaign in
South West England, Harley served as captain of a troop of cavalry at
Lansdowne and
Roundway Down in July. Two Parliamentarian defeats that cemented Royalist control of the region, he later attributed these setbacks to divine punishment for over confidence. However, an
attack on Gloucester itself was successfully repulsed, and in August Harley was made
colonel of a new infantry regiment raised as part of Massey's Army of the Western Association. Lady Brilliana died of pneumonia in October 1643, while Brampton Bryan castle was sacked and burned a few months later. During a Royalist attempt to tighten their
blockade of Gloucester in August 1644, Harley was wounded in a skirmish outside
Redmarley D'Abitot, a village near
Ledbury. This was repulsed, and with
Prince Rupert taking many Royalist troops north for the
Marston Moor campaign, Parliamentarian forces were able to capture
Monmouth in September. Harley was appointed Governor, before dissension among the garrison and hostility from the locals allowed the Royalists to retake the town in November. When the
New Model Army was formed in April 1645, Harley was given command of one of its twelve authorised infantry regiments; the previous colonel, Harry Barclay, and his deputy John Innes, were Scottish professional soldiers who resigned under orders from the
Covenanter government. His appointment appears to have been a political decision, since many officers proposed by
Oliver Cromwell and Sir
Thomas Fairfax were religious
Independents or political radicals. Their commissions had to be approved by Parliament, whose moderate Presbyterian majority viewed them with considerable unease. Parliament presumably hoped Harley would counterbalance some of his radical officers, which included
Lieutenant Colonel Thomas Pride, leader of
Pride's Purge in December 1648, and future
regicide Captain
William Goffe. In reality, command was generally exercised by Pride, since Harley spent very little time with the regiment. He missed
Naseby after being wounded in another skirmish outside Ledbury in April 1645, and was appointed Governor of
Canon Frome in August, which meant he did not participate in the New Model's Western Campaign. Regional forces like Massey's Western Association continued to exist independently of the New Model, and in January 1646 Harley was appointed Commander of Horse for Herefordshire and
Radnorshire. He was also one of the delegates who negotiated the surrender of
Oxford, the Royalist war-time capital whose capitulation in June 1646 effectively ended the war. However, victory resulted in increasingly bitter disputes over the post-war political settlement between radicals within the New Model like
Oliver Cromwell, and Parliamentary moderates, the most prominent being
Denzil Holles. At the same time, Parliament's desperate economic position made reducing the number of men under arms a matter of urgency. Seeking to ensure his own troops were retained and to re-assert his position in local politics, Harley became involved in a power struggle with the other prominent Parliamentarian in the region, Colonel
John Birch, Governor of Hereford. In September 1646, Harley supported a proposal to dissolve those forces commanded by Birch, whom he then defeated in a By-election for
Herefordshire. Although the
Self-denying Ordinance required
MPs to resign their military positions, Harley retained his commission in the New Model. However, once in Parliament he sided with those who feared and resented the growing political influence of the military, and became one of its most significant opponents. Along with Holles, Waller and Massey, in June 1647 he was among the
Eleven Members the army demanded be removed from Parliament. The MPs complied, allegedly "to avoid bloodshed". ==Pride's Purge and the Interregnum==