The cessation created an opportunity for both Ormond and the Catholic Ear of Antrim to reinforce Royalist forces in Scotland and England. Early in the year while there was much discussion about the Army of Ulster returning to Scotland to serve under Leven’s expedition into England, three regiments left Ireland for Scotland of their own accord. Sinclair’s, Lothian’s and Lawer’s Regiments all departed Ireland and eventually joined Leven in England. In 1644 Ormond sent regiments to Bristol and Chester, which were destroyed at Naseby and Langport. The Earl of Antrim sent three regiments of Irish mercenaries totaling perhaps as many as 2,000 men, recently released from Spanish service, to support the Marquis of Montrose in Scotland. Despite the transfer of forces to England and Scotland, both Ormond and Monro retained sufficient forces to influence events in Ireland. Parliament recognized Monro as the commander of all English and Scottish forces in Ulster and resupplied him, perhaps in the hopes that he could prevent other regiments from deserting Ireland. He made an attempt to take Dundalk and Drogheda in the name of Parliament and failed. Monro, concerned about Sir Arthur Chichester’s occupation of Belfast, acceptance of the cessation and denouncing of the covenant occupied Belfast without firing a shot on 14 May 1644 disbanding Chichester’s regiment in the process.
The cessation caused a split in the Laggan Army, part of which followed the lead of Sir Robert Stewart and complied with the terms of the cessation. Another part of the Laggan army under the lead of Sir Thomas’s brother William sided with Monro and did not accept the terms of the cessation.
In April, the Army of Ulster followed Scotland’s lead by agreeing to the Solemn League and Covenant but the Ulster settlers were divided into those who would and those who would not follow the Earl of Ormond and his royalists. With plans in the works for an invasion of England in support of Parliament, the Scots settlers provided many of the soldiers for the new Scottish Army. By June Monro, supported by elements of the Laggan Army, was prepared to advance toward an army led by the Earl of Castlehaven and moved south into Leinster, capturing Granadard and Longford as well as burning Kells and Navan before running low on supplies and withdrawing north back into Ulster. Castlehaven’s army retreated as Monro advanced but by July, entered Ulster. Monro advanced to Kilwarlin Woods waiting for Argyll’s and Leven’s regiments but in the process ran out of supplies delaying his advance until he could forage in the local area. By August once reinforced by the Lagan army and re-supplied, he advanced into Armagh finding himself in a stalemate with Castlehaven until September and unable to follow due to bad weather he withdrew, having forced Castlehaven south to Clones.
Monro’s successes in Leinster may have influenced the Earl Inchiquin, commander of Royalist forces in Munster, to declare for Parliament in July, as it seemed that the royalists were unable or unwilling to take action to support the protestants in Ireland. This change gave Parliament access to the ports of Youghal, Cork and Kinsale giving them the option of landing and supplying their own forces in Ireland.
The Army of Ulster by the end of the year once again found itself neglected and short on supplies and all sides wanting it to remain in Ireland. It began, however, to operate independent of both Scotland who wanted it to send more troops to Scotland which it refused to do and English demands that Belfast be turned over to Parliament went unheeded.