And what happened on the 3rd of September?

The Battle of Worcester was not a single action, and instead there were two distinct phases, one taking place in the early afternoon, the other in the late afternoon, and on until nightfall.

Those phases took place in different geographical locations, and in the main involved different bodies of troops.

The Battle of Worcester is thus nothing like most of the other major battles of the main civil war, notably Edge Hill, Marston Moor and Naseby, where the two armies drew up in matching lines parallel to each other and then engaged along the line.

It was far more disjointed.

The first phase of the battle, beginning around noon and lasting around three hours, involved the 12,000 or so troops which Cromwell had deployed west of the Severn, moving forward northwards towards the city.

Their objective was to force a crossing of the River Thieme, which ran roughly west to east, a little over a mile south of Worcester, down to its confluence with the Severn.

many other of the Scots nobility have left the noise and tumult of war for places of safety and retiredness.

Why were the Scots supporting the royalist cause? And why in 1650-51 were they seeking to restore Charles Stuart, the son and heir of the late Charles I, to power in England as well as Scotland? After all, hadn't they allied with and supported the English Parliamentary Army in the main civil war of 1642-46?

Yes, indeed they had.

Via a treaty signed in summer 1643, the Solemn League and Covenant, the Scottish army had agreed to enter England and fight alongside Parliament's armies against Charles I's royalist forces.

They had done so in part because they feared that a king triumphant in England would turn his attention back to Scotland and seek not only to reimpose his royal secular power there, but also to resume his attempts to meddle with the Scottish Presbyterian Church and to impose a more anglicised form of religion north of the border.

But they'd also allied with Parliament in return for a pledge that, once the Civil War had been won, Parliament would impose a Presbyterian-style religious settlement in England and Wales.

The Scots had kept their side of the bargain, committing an army of 20,000 men south of the border, which had turned the tide of the Civil War decisively in Parliament's favour in northern England in 1644 – even if the Scots' direct military contributions in the Midlands and the South had been rather more muted in 1645-6.

But they became aware that many English parliamentarians, army officers and senior politicians were antipathetic to their new Scottish allies and downright hostile to the prospect of a Scottish-style Presbyterianism being imposed in England and Wales.

Why in summer 1651 didn't Cromwell lead the army to attack the new Royalist base at Stirling? Why was he reluctant?