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
Battle of Selby fairly short order the town fell. With the fall of the town huge stocks of munitions and more than 1,500 Royalist soldiers were lost to the Parliamentarians. The road from Hull to York was now opened for a Parliamentary advance on York, which they were able to besiege. When Royalist forces under Prince Rupert, relieved York and combined with the garrisons forces, Rupert felt strong enough to engage in the pitched Battle of Marston Moor, however the Parliamentarians and Scottish Covenanters won the battle and with that victory consolidated their position in the north-east, depriving the Royalists of the area.