reforms. Both sides struggled to properly supply troops fighting outside their home regions and Parliament agreed steps to mitigate the problem. Seeing an opportunity to force Parliamentary moderates into a negotiated peace, in September the Royalists agreed a new three-part offensive. After taking Gloucester, Prince Rupert would advance on London, while Newcastle would tie down the Eastern Association army by advancing into East Anglia and Lincolnshire. Finally, Hopton would march into Hampshire and Sussex, threatening London from the south, and closing the iron foundries that were Parliament's main source of armaments. However, Essex forced Prince Rupert to retreat from Gloucester, then checked his advance on London at Newbury on 20 September. Although Hopton reached Winchester, Waller prevented him making further progress; in October, Newcastle abandoned the second siege of Hull, while victory at Winceby secured eastern England for Parliament. Royalist failure ended any chance of concluding the war in the near future, leading both sides to step up the search for allies. In September, the Royalists in Ireland agreed a truce with the Catholic Confederation, allowing Ormond to transfer troops to England but cost Charles the support of many Irish Protestants, especially in Munster. At the same time, details emerged of the "Antrim scheme", an alleged plan to use 20,000 Irish troops to recapture Southern Scotland for Charles; although highly impractical, the Covenanter government ended negotiations with the Royalists. Shortly thereafter, they signed the Solemn League and Covenant, agreeing to provide Parliament military backing in return for subsidies, and discussions on creating a single, Presbyterian church. 1644 The Solemn League created a Committee of Both Kingdoms to co-ordinate strategy in all three war zones, England, Scotland and Ireland, although Pym's death in December 1643 deprived Parliament of their most important leader. The Scots under Leven were ordered to take Newcastle, securing coal supplies for London, and closing the major import point for Royalist war supplies. He besieged the town in early February, but made little progress, observed by the Earl of Newcastle from his base in Durham. On 29 March, Waller ended the offensive in Southern England by defeating Hopton at Cheriton, then joined Essex to threaten Oxford. Two weeks later, the Earl of Manchester defeated a Royalist force at Selby, forcing Newcastle to leave Durham and garrison York. The city was besieged by the Scots, Sir Thomas Fairfax, and Manchester's Army of the Eastern Association. In May, Prince Rupert