The English Civil War had divided the country roughly along social and religious lines. The North, the West, and Catholic Ireland leaned Royalist; the South East and Presbyterian Scotland leaned Parliamentarian. Newcastle was a Royalist stronghold - and crucially, the source of the coal that warmed London. Hold Newcastle, and you held the Crown's economic lifeline. Lose Newcastle, and Parliament could control prices in the capital. The Scots Covenanters, allied with Parliament under the Solemn League and Covenant, had already occupied the city briefly during the Second Bishops' War in 1640. They knew the ground. In January 1644, Lord General Alexander Leslie, 1st Earl of Leven, crossed the border at the head of a Scottish army and marched south.

Leven left six regiments under Lieutenant General James Livingstone, 1st Earl of Callander, to invest Newcastle while the main army pressed on. The siege was not a continuous strangulation. Callander diverted forces to take Newburn and other towns along the Tyne; the city was sometimes blockaded, sometimes only watched. Sir John Marlay used the gaps to strengthen the walls and to send men south to join the main Royalist field army. Then, on 2 July 1644, the Royalists were shattered at Marston Moor. Prince Rupert's army was broken; the North was effectively lost. After Marston Moor, no relief column would be coming for Newcastle. The defenders on the walls knew it. They held on anyway.

On 15 August 1644, with Leven's main army now joining Callander, the serious bombardment began. Scots gunners pounded the medieval walls; engineers tunneled mines beneath the fortifications and blew sections of stone into the streets. The western half of the wall fell on 19 October. Marlay and the remaining loyalists pulled back into the Norman Castle Keep that still stands at the heart of the city. There was no relief, no hope of resupply, no honourable strategy left except a negotiated surrender. On 27 October 1644, Marlay accepted Leven's terms. The terms were generous by the standards of the war - the garrison was spared, the city largely intact - but Marlay himself was imprisoned, and several leading Royalists were banished from England.

The Covenanters took control of the Tyneside coal trade for the second time, holding it until 30 January 1647 when the Solemn League and Covenant unraveled and the Scots withdrew. Tynemouth had fallen the same day as Newcastle. The English Parliament, oddly, was less delighted than the Scots; the price of having a foreign ally hold the coal supply was being made to wait, and pay, on Scottish terms. The walls Marlay had defended were eventually repaired, but the Civil War had broken something more durable than masonry. Newcastle's Royalist mercantile class lost influence in the new England; the apprentices who had marched on the walls grew up under a different settlement. The Castle Keep, where the last defenders held out, still rises over Newcastle's railway tracks - a reminder of the autumn the city ran out of options.