The war had advanced to the stage where the Parliamentary forces were seeking to control far larger swathes of territory, and were defeating Royalistpockets of resistance throughout the Midlands, Wales, and into the north. York, by now the King's main centre in the north, would be the eventual target of the Roundhead army, but prior to taking on the forces there, other strongholds would have to be dealt with. Selby was one such place, commanding the routes to York and the vital port of Hull, and as the strong point on the RiverOuse of immense strategic importance in the movement of troops and goods in the area. The region itself was the key to developments in the conflict, Royalist forces in the area making a barrier between Parliament's and the Scots to the north.
Battle
The Royalists under John Belasyse fortified Selby, with barricades and the flooding of the dam fields to one side of the town. The Fairfaxes, Lord Fairfax and his son Sir Thomas Fairfax, decided on attacking from three directions at once, hoping to find the weak point in the town's defences and penetrate them. Once inside the defensive ring they expected to secure victory with ease. This might have been regarded as a dangerous strategy, opening the smaller units to counter-attack, and with communications between the three forces made extremely difficult to coordinate. Thus Meldrum attacked the barricades from the east, Needham those in the west, and Thomas Fairfax at Ousegate, where after stern resistance the breakthrough was made. As expected, once inside the town the Roundheads had the enemy at an enormous disadvantage, attacked from front and rear. In fairly short order the town fell.
Aftermath
With the fall of the town huge stocks of munitions and more than 1,500 soldiers were lost to the Royalists. 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.