While the Jacobite army was waiting on Lesbury Common for news from Scotland or France, Cotesworth and the Lord Lieutenant of Northumberland, the Earl of Scarborough, acted with great efficiency to secure Newcastle. The town militia and trained bands were called out and allotted defence stations on the walls.
The Northumbrian Militia mustered on Killingworth Moor and then deployed around Newcastle. A body of 700 volunteers was raised to defend the town, and 700 keelmen also came forward. Many of the local gentry rode into Newcastle to offer their services to the House of Hanover. A loyal association was signed by the town's inhabitants, declaring loyalty to King George. Catholics and those suspected of Jacobite sympathies were imprisoned. The houses of Catholics were raided in County Durham and their arms and horses removed. Spies were posted across Durham and Northumberland to report on Jacobite intentions.
The Jacobites, too, were active. Derwentwater sent regular dispatches to his wife at Dilston, and had tried to establish an intelligence network in Newcastle. Unfortunately, his chief agent, Thomas Lisle, was caught and he revealed to the High Sheriff Jacobite plans to take Tynemouth Castle. Under the ever-watchful eyes of Clavering and Cotesworth, the Government forces were winning the intelligence war in the area. However, it is clear from contemporary reports and letters that there was widespread panic, especially in Newcastle, and a lack of knowledge as to Jacobite plans. As the Jacobites themselves had no clear plan yet, this is perhaps hardly surprising! On 10 October the fears of the citizens were somewhat allayed by the arrival of regular troops in the town.
The Jacobites, meanwhile, had spent the week organising their army into troops and appointing officers. On 10 October Lancelot and Mark Errington had successfully secured Holy Island Castle without bloodshed, but for some reason Forster failed to send troops to support them. Next day the arrival of a body of men from the garrison at Berwick forced the Erringtons to surrender. One of the great opportunities of the Rising had been missed. Forster, however, had serious troubles of his own, for Colonel Hotham's Regiment arrived in Newcastle on 10 October.
Forster had not foreseen the rapid arrival of Government forces in the county, and at first refused to believe it. Eventually, however, he was persuaded to sent Hunter's Troop of seventy Borderers to hold the bridge at Felton against Hotham's men.
Holy Island Castle in the 19th Century