Rupert's March to York 1644
Jun 3 Manchester arrives at York to join the Scots under Leven and Fairfax's army. Newcastle and Eythin were besieged inside the city.
Jun 14 Charles wrote a letter to Rupert asking him to relieve York and destroy the besieging armies.
But now I must give the true state of my affairs, which if their condition be such as enforces me to give you more peremptory commands than I would willingly do, you must not take it ill. If York be lost I shall esteem my crown little less; unless supported by your sudden march to me; and a miraculous conquest in the South, before the effects of their Northern power can be found here. But if York be relieved, and you beat the rebels' army of both kingdoms, which are before it; then (but otherwise not) I may possibly make a shift upon the defensive to spin out time until you come to assist me. Wherefore I command you, by the duty and affection that I know you bear me, that all new enterprises laid aside, you immediately march according to your first intention, with all your force to the relief of York. But if that be either lost, or have freed themselves from the besiegers, or that 'for want of powder, you cannot undertake that work, that you immediately march with your whole strength, directly to Worcester, to assist me and my army; without which, or your having relieved York by beating the Scots, all the successes you can afterwards have must infallibly be useless unto me. You may believe that nothing but an extreme necessity could make me write thus unto you; wherefore in this case, I can no ways doubt of your punctual compliance with Your loving and most faithful friend, Charles R. Part of the letter received by Rupert from the King, asking him to relieve the siege of York.
Jun 23 Rupert left Preston to help relieve York, passing up the Ribble valley, through Clitheroe and Gisburn.
Jun 26 He arrives at Skipton where he halts for 3 days to prepare his troops for action and send messages to York for intelligence about the enemy's position. Rupert's army must have consisted of at least 14,000 men.
Jun 28 The parliamentarian forces besieging York heard that Rupert had reached Skipton, and, not wanting to confront him in York, they lifted the siege and marched to take up a position on the Knaresborough to York road on a wide area of heath near the village of Long Marston. They thought this would be a good position to cut off Rupert's advance to York. The Earl of Denbigh and Sir John Meldrum were on their way to help the Parliamentarian forces with forces from the Midlands but were still some four days short.
Jun 30 After two days marching Rupert arrives at Knaresborough.
A bridge of boats had been built at Poppleton, 4 miles north of York, to allow parliamentarian troops that were to the North of York to join the main army.
Rupert wanted to link up with Newcastle's forces inside York before confronting the enemy, so he detoured with his main army to the north. He had sent a strong detachment of horse along the York road to give the impression that was the route he was going to attack from.
Jul 1 The surprise was so great that the troops guarding the bridge of boats and the few troops guarding the siege works were easily overwhelmed. This allowed Rupert to cross the river Ouse, relieve York and join up with the besieged men inside the city.

The decoy detachment of horse also rejoined the main army in the night.

 Goring went into the city to give a message to Newcastle to join Rupert with as many men as possible by 4 am the next morning.
Rupert needed to join battle quickly despite his exhausted army and the fact that he was heavily outnumbered. His tactic of detouring north had caused the Parliamentarian armies to be facing the wrong way. He knew that there were more troops coming with Meldrum and Denbigh to help the Roundheads. He was also in a hurry to move south and help the King who he believed was in trouble.

Rupert sent a detachment of horse south from the city to give the impression that his next move was to go south into Lincolnshire.
Jul 2 Rupert continued in the early hours to get his troops across the bridge of boats.

The parliamentarian foot led by the Scots, had started to march south towards Tadcaster to cut off any move made by Rupert while a little over half of the horse under Fairfax, Cromwell and Leslie deployed along a ridge to the south of the road between Long Marston and Tockwith.

To the north of the road was Marston Moor.