Battle of Kilrush The Battle of Kilrush was a battle at the start of the Eleven years war in Ireland , soon after the Irish Rebellion of 1641 . It was fought in April 1642 between a Royalist army under the Earl of Ormonde , and Richard Butler , 3rd Viscount Mountgarret , who led newly formed units of Confederate Irish troops raised during the Irish Rebellion of 1641 . Ormonde and Mountgarret were cousins , both being members of the Butler dynasty . Campaign . Ormonde ' s troops left Dublin on 2 April and marched on unopposed from Naas to Athy ( 5 April ) and on to Maryborough ( now Portlaoise ; 8 April ) , re - supplying the royalist garrisons and sending cavalry forces to support those at Carlow and Birr , before returning to Athy on 13 April . Setting out at 6am on the 15th , and having decided to avoid a battle on their return march to Dublin , the government troops were blocked by Mountgarret ’ s rebel militias at Kilrush , 2 miles south of Suncroft , between Kilcullen and Moone in south - eastern County Kildare . Though outnumbered , Ormonde managed to defeat the rebels and marched on to Dublin by 17 April . Details . The Dublin Penny Journal of the 1800s said that : “ The land in the neighbourhood of Inch Castle lies remarkably flat , with the exception of two ridges that run nearly parallel northward from the castle , with a marsh lying between . It was in these heights the armies of Ormond and Mountgarrett , in 1642 , marched in sight of each other , the evening previous to the battle of Kilrush ; that of Ormond on the high grounds of Ardscull , Fontstown , and Kilrush , whilst the rebel army under Mountgarrett , and attended by the Lords Dunboyne and Ikerrin , Roger O ’ More , Hugh O ’ Byrne , and other leaders of Leinster , proceeded in the same direction along the heights of Birtown , Ballyndrum , Glasshealy , and Narraghmore . Mountgarrett , having the advantage in numbers , and anxious for battle , out - marched Ormond ’ s forces , and posted himself on Bull Hill and Kilrush , completely intercepting Ormond ’ s further progress to Dublin ; a general engagement became unavoidable . The left wing of the Irish was broken by the first charge ; the right , animated by their leaders , maintained the contest for some time , but eventually fell back on a neighbouring eminence , since called Battlemount ; here they broke , fled , and were pursued with great slaughter , across the grounds they had marched over the day before . This victory was considered of such consequence that Ormond was presented by the Irish Government with a jewel , value £50 . ” A contemporary account of the battle was given in the pamphlet : " Captaine Yarner ' s Relation of the Battaile fought at Kilrush upon the 15th day of Aprill , by my Lord of Ormond , who with 2500 Foot and 500 Horse , overthrew the Lord Mountgarret ' s Army , consisting of 8000 Foot and 400 Horse , all well armed , and the choyce of eight Counties . Together with a Relation of the proceedings of our Army , from the second to the later end of Aprill , 1642 . " The Jacobite historian Thomas Carte ' s life of Ormonde ( 1736 ) describes the campaign and the battle casualties . " In this battle there were twenty English slain , and about forty wounded . . . the rebels lost above seven hundred killed outright , among which were several colonels . . " .