The following units and commanders fought in the Battle of Naseby during the First English Civil War. Parliamentarian New Model Army (6000 Horse, 1,000 Dragoons, 7,000 Foot, 11 guns) Lord General Sir Thomas Fairfax Left Flank Colonel John Okey's Regiment of Dragoons Left Wing (Commissary General Henry Ireton) First Line Colonel John Butler's Regiment of Horse Colonel Cornelius Vermuyden's Regiment of Horse Commissary General Henry Ireton's Regiment of Horse Second Line Colonel Nathaniel Rich's Regiment of Horse Colonel Charles Fleetwood's Regiment of Horse Eastern Association Horse (half regiment) Centre (Sergeant Major General Sir Philip Skippon) Eleven pieces of artillery First Line Sir Philip Skippon's Regiment of Foot Sir Hardress Waller's Regiment of Foot Colonel John Pickering's Regiment of Foot Colonel Edward Montagu's Regiment of Foot Sir Thomas Fairfax's Regiment of Foot Forlorn Hope of commanded musketeers Second Line Lieutenant Colonel Pride's Regiment of Foot Colonel Robert Hammond's Regiment of Foot Colonel Thomas Rainsborough's Regiment of Foot Third Line Lieutenant Colonel Pride's Reserve Right Wing (Lieutenant General Oliver Cromwell) First Line Colonel Edward Whalley's Regiment of Horse Sir Robert Pye's Regiment of Horse (one Division) Sir Thomas Fairfax's Regiment of Horse Colonel Edward Rossiter's Regiment of Horse (one Division) Second Line Colonel Thomas Sheffield's Regiment of Horse Sir Robert Pye's Regiment of Horse (one Division) Colonel John Fiennes's Regiment of Horse (one Division) Third Line Eastern Association Horse (half regiment) Colonel John Fiennes's Regiment of Horse (one Division) Colonel Edward Rossiter's Regiment of Horse (one Division) Royalist Army (4,100+ Horse, 3,300+ Foot) King Charles I General of the Army Prince Rupert Left Wing (Sir Marmaduke Langdale) Four Divisions of "Northern Horse" Colonel Sir Horatio Cary's Regiment of Horse Centre (Lord Astley) Three divisions of Colonel Sir Thomas Howard's Regiment of Horse Sir George Lisle's Tertia Sir George Lisle's Regiment of Foot Colonel William St. George's Regiment of Foot The Shrewsbury Foot (the remnants of several regiments returned from Ireland, including Tillier's, Broughton's, Warren's and Gibson's, under Colonel George Smith) Sir Henry Bard's Tertia Sir Henry Bard's Regiment of Foot Colonel Rhys Thomas's Regiment of Foot Sir John Owen's Regiment of Foot Colonel Richard Bagot's Regiment of Foot Colonel Ratcliffe Gerard's Regiment of Foot Sir Bernard Astley's Tertia The Duke of York's Regiment of Foot Colonel Sir Edward Hopton's Regiment of Foot Colonel Sir Richard Page's Regiment of Foot Right Wing (Prince Maurice) First Line Prince Rupert's and Prince Maurice's Lifeguard Troops