Oliver Cromwell with Sir Thomas Fairfax in command and Cromwell as Lieutenant-General of cavalry and second-in-command. At the critical Battle of Naseby in June 1645, the New Model Army smashed the King's major army. Cromwell led his wing with great success at Naseby, again routing the Royalist cavalry. At the Battle of Langport on 10 July, Cromwell participated in the defeat of the last sizeable Royalist field army. Naseby and Langport effectively ended the King's hopes of victory, and the subsequent Parliamentarian campaigns involved taking the remaining fortified Royalist positions in the west of England. In October 1645, Cromwell besieged and took
William Eyre (leveller) New-England because he opposed the Service Book. In 1642 Eyre was a sergeant in Denzil Holles's regiment, and fought at Battle of Edgehill. Just over three weeks later he was with the regiment when it was destroyed by a detachment of the Royalist army under the command of Prince Rupert at Battle of Brentford. Eyre joined the Eastern Association and was commissioned by Oliver Cromwell a quartermaster in his own troop. Shortly afterwards he was promoted to captain of the sixth troop in Cromwell's regiment of horse (the famous Ironside). He fought under Cromwell in the Lincolnshire campaign of 1643.