The battle occurred when an English force under Colonel Daniel Axtell attacked the Connacht Irish army led by Ulick Burke, 1st Marquess of Clanricarde.
Clanricarde was the leading Irish commander in the province and by August recognised as the de facto successor to Ormond as Lord-Lieutenant of Ireland.
Colonel Axtell, the English commander in the region, was forced over the River Brosna and then to Birr after some skirmishes between his regiment and the Irish army.
[1] However, English reinforcements under Colonels Cook and Abbot quickly marched up from Wexford and Kilkenny to join Axtell at Roscrea on 21 October.
When Axtell advanced towards Birr to challenge the Irish army, Clanricarde decided to withdraw and to take up formidable defensive positions on Meelick Island, a Crannog on the River Shannon.