Battle of Scarrifholis The Battle of Scarrifholis was fought in Donegal North - West Ireland , on 21 June 1650 , during the Irish Confederate Wars – part of the Wars of the Three Kingdoms Cogadh ná Trí Ríocht . It was fought between the Ulster Army ( Catholic ) , commanded by Heber MacMahon , Roman Catholic Bishop of Clogher , and an English Parliamentarian army commanded by Charles Coote and composed of troops from the New Model Army and local Ulster Protestant settlers . The battle resulted in the annihilation of the Ulster army and the loss of most of its weapons and supplies . This secured the north of Ireland for the English Parliament and contributed greatly to the Cromwellian conquest of Ireland . Background . The Ulster Army was raised by the Irish Confederate Catholics in 1642 to organise the insurgent forces who were operating there since the rebellion of the previous year . Up to 1649 , it was commanded by Owen Roe O ' Neill , a professional soldier who had served in the Spanish army in Flanders . However , O ' Neill died in late 1649 and was replaced by Bishop Heber MacMahon of Clogher . MacMahon had no real military experience , but was elected by the Ulster officers to avoid political infighting among their officers . The army was split between those who supported the Confederate ' s treaty with the English Royalists , mainly pre - war land - owners such as Phelim O ' Neill and the army ' s professional officers and Catholic clergy who did not support a deal with the Royalists that did not guarantee the public exercise of the Catholic religion and return confiscated lands to Catholic landowners . In 1648 , Owen Roe O ' Neill had left the Confederation and briefly fought with the other Confederate armies over the treaty with the Royalists . He even negotiated with the English Parliamentarian forces in Ulster to try to secure a better deal for Catholic interests . He only re - joined the Catholic Confederation after the invasion of Ireland by Oliver Cromwell in August 1649 , when it was clear that the English Parliament was the most dangerous enemy faced by Irish Catholics . On the other side , the English and Scottish Protestant forces in Ulster had also been split by the events of the English Civil War . Up to 1649 , the Protestants were led by the Scottish Covenanters , based in Carrickfergus and a British settler army based around Derry . However , in 1649 , following the execution of Charles I by the English Parliament , the Protestants split into Royalist and Parliamentary factions . Most of the English settlers like Charles Coote sided with the Parliament ( primarily because they disliked the Royalist ' s conciliatory attitude to Irish Catholics ) and they took control of Derry . They were joined by a Parliamentary army sent to the Ulster by Oliver Cromwell in 1649 commanded by Robert Venables and Theophilus Jones . The Scots on the other hand , sided with the Royalists . In 1648 , Royalists in Ulster had besieged Coote at Derry , but Coote held out . The following year , the Scots and Royalists in Ulster were routed by Venables at the battle of Lisnagarvey in Antrim . After this point , the Parliamentarians assumed command of the war against the Ulster army . The campaign . Bishop MacMahon assembled the Ulster army in Loughgall in south Armagh , with 4000 infantry and 600 cavalry . They were , however short of ammunition and over half of their men carried pike s rather than muskets ( whereas the norm at the time was one pike for two muskets ) . His aim was to march through the centre of Ulster and divide Coote ' s garrison at Derry in the west of province from Venables ' command at Carrickfergus in the east . With the Parliamentarian troops engaged by the activities of Irish guerrillas or " Tories " , the Ulster army marched on Ballycastle situated on the northern coast of Ulster deploying garrisons along the centre of the province . They then marched west , towards Coote ' s army located at Lifford ford , near Strabane , Co . Tyrone . Fending off an attack by the English cavalry as they crossed the river Finn , the Irish encamped in the Doonglebe / Tullygay hill overlooking the Ford at Castle Sollus ( tower house ) Scarrifholis , 2 miles west of Letterkenny ( on the present day R250 ) . The local Protestant population fled to the fortified towns in the area , as the war in Ulster had , from its outset , been characterised by indiscriminate atrocities committed against civilians by both sides . Meanwhile , Parliamentarian reinforcements had joined Coote from eastern Ulster , bringing his forces up to 3000 men , compared to 4000 Irish . However , the British force had more ammunition and more cavalry than their enemies . MacMahon ' s officers warned him not to leave their strong defensive position and risk battle , as the Parliamentary army was tactically superior to them . Rather , they should stay put and wait for the enemy to disperse when their supplies ran out , leaving the Irish free to march back to their stronghold along the border with Leinster . Allegedly MacMahon refused to listen to military advice and ordered his troops down from their mountain camp to give battle to the Parliamentary army although much of his cavalry was engaged in domestic issues in Kilmacrennan . The battle . MacMahon ' s inexperience was further exposed in how he drew up his troops for battle . He placed a small advance guard in front his army and positioned the rest of his troops in a huge solid mass , which meant that it would be very difficult to manoeuvre and very few units could actually engage the enemy , being stuck within the ranks of their own men . Coote , meanwhile , who had been fighting since 1641 and whose father had been a professional soldier , drew up his men in small flexible units – able to reinforce one another and to move around the battlefield . The battle started when Coote sent an infantry detachment to meet the Irish advance party . The two sides exchanged musket volleys at close range and then fought hand to hand with pikes and musket butts . However , Coote steadily reinforced his infantry and eventually drove the Irishmen back into the front of their formation . Because of the deployment method MacMahon adopted , it hemmed in the front ranks of the Ulster army , who were trapped behind their own panicked skirmishers and the pursuing Parliamentarian infantry . Seeing his chance , Coote sent more infantry to attack the flanks of the Irish formation , trapping the whole force between his men and the mountain , which was their initial position of advantage which they descended from to engage Coote ' s troops . The predicament the Ulster Army found itself in was a similar to the Roman army that Hannibal destroyed at battle of Cannae in 216 BC . Although they still outnumbered their enemies , they were pinned in dense uncoordinated mass , unable to defend themselves against the troops who had surrounded them . Increasingly , they were a mob of terrified individuals rather than a disciplined military unit . The fact they were also very short of ammunition meant that the Parliamentarians were able to pour volleys into this dense mass without effective reply , cutting down their quarry from a distance . At this point , all was lost , and their leaders and horsemen fled the battlefield , pursued by the Parliamentarian cavalry and by the local Protestant population – seeking revenge for massacres at the hands of the Irish in 1641 – 42 . Nevertheless , the doomed Ulster infantry fought doggedly until they were slaughtered at Meenaroy , Stranabratog and Welshtown after fleeing over Cark mountain into Cloghan . Interestingly two - thirds of the Irish dead were found on the battlefield itself rather than along the line of pursuit which stands as stark testament to the determination of the Ulster troops knowing Coote ' s reputation as a merciless killer and breaker of treaties . Aftermath . The battle was a decisive victory for Coote and Parliamentarian forces in the region . Over 3000 of the Ulster army were killed – 2000 on the field and another 1000 in the pursuit – about 75 % of their total numbers . The Parliamentarians lost only around 100 soldiers killed . Coote ordered that Irish wounded and prisoners taken were to be killed ( Meenaroy , Stranabratog and Welshtown ) including Henry O ' Neill , Owen Roe O ' Neill ' s son , who had surrendered on terms . MacMahon was captured a week later at Enniskillen and hanged . The battle marked the destruction of the Ulster army the only remaining military obstacle to pacifying Ulster , the loss of men and material coupled with the loss of much of the many experienced officer cadre in all reality removed the Ulster army as a operational force , with time these loses could be turned around but time was now the enemy . In addition to O ' Neill and MacMahon , the Irish lost 9 Colonels , 4 Lieutenant Colonels , 3 Majors , 20 Captains and much of their junior officers corps . This represented a huge cull of the Ulster ' s , Gaelic Irish and Anglo - Irish elite , more significant than that which occurred in 1607 with the Flight of the Earls . For this reason , the battle has been described as ' Ulster ' s Aughrim ' – furthermore this particular battle marked the decline of the province ' s native aristocracy through the attrition of battle , disease and existing in a land at war for the best part of eight years , this consequently assured the successful planting and supremacy of a new wave of colonist orientated settler population . Coote went on to besiege Charlemont , the remaining stronghold held by the Ulster Army under Phelim O ' Neill despite taking severe losses in several failed assaults , O ' Neill surrendered the fort to Coote in August 1650 . Coote ' s army proceeeded to march south , taking Sligo and then Galway after a long siege in 1652 . The surrender of this city marked the effective end of the Confederacy of Kilkenny resistance to the Cromwellian conquest of Ireland .