Thirty Years' War. Many of the regiments had served during the Bishops' Wars in Scotland (1639-1641) and the Irish Rebellion of 1641. The infantry was thus a mix of experience, with new and old regiments both containing officers and men with continental experience. Those with siege experience had been left investing Newcastle under a veteran of Dutch service, Lieutenant General the Earl of Callandar. The cavalry used smaller and lighter mounts than English units. Those on the left wing were placed in the rear of Cromwell's horse; on the right, Eglinton's horse were alongside Fairfax's regiment in the front rank and Leven's and Dalhousie's regiments in the rear. Parliamentarian Army of the Eastern Association (3000 Horse, 4000 Foot) Captain General Earl of Manchester Lieutenant General of the Horse Oliver Cromwell Commissary General Bartholomew Vermuyden Earl of Manchester's Regiment (Lieutenant Colonel Algernon Sidney: 11 troops) Lieutenant General Cromwell's Regiment (Lieutenant Colonel Edward Whalley: 14 troops) Commissary General Bartholomew Vermuyden's Regiment (5 troops) Charles Fleetwood's Regiment (6 troops) Dragoons Lieutenant Colonel John Lilburne (6 companies) (Manchester's dragoons had been defeated on 1 July at Poppleton.) Sergeant-Major General of the Foot Lawrence Crawford Earl of Manchester's Regiment (Lieutenant Colonel Clifton: 18 companies) Major General Crawford's Regiment (Lieutenant Colonel William Hamilton: 8 companies) Sir Miles Hobart's Regiment (9 companies) Francis Russell's Regiment (10 companies) Edward Montagu's Regiment (10 companies) John Pickering's Regiment (10 companies) (Russell's, Montagu's and Pickering's regiments were brigaded together. Some of these would have taken heavy casualties at a failed storming of York on 16 June) This army was raised in the Eastern Counties of England (Norfolk, Suffolk, Essex, Cambridgeshire and Huntingdonshire). Although there were religious tensions within the army between the Independents, championed by Cromwell, and the Presbyterians who were backed by Manchester and Crawford, there was no argument on the day of battle. Parliamentarian Army of Ferdinando, Lord Fairfax (2000 Horse, 2000 Foot) General Lord Fairfax Lieutenant General Sir Thomas Fairfax Sergeant-Major General of the Horse John Lambert Lord Fairfax's Regiment Sir Thomas Fairfax's Regiment Charles Fairfax's Regiment Sir Hugh Bethell's Regiment John Lambert's Regiment Lionel Copley's Regiment Francis Boynton's Regiment Sir Thomas Norcliff's Regiment George Dodding's Regiment Dragoons Thomas Morgan Sergeant-Major General of Foot (unknown) Lord Fairfax's Regiment John Bright's Regiment Sir William Constable's Regiment Francis Lascelles's Regiment Robert Overton's Regiment Ralph Ashton's Regiment George Doddington's Regiment Alexander Rigby's Regiment The list of Colonels and regiments is probably