Siege of Kinsale The Siege or Battle of Kinsale ( ) was the ultimate battle in England ' s conquest of Gaelic Ireland . It took place at the end of the reign of Queen Elizabeth I , at the climax of the Nine Years War - a campaign by Aodh Mór Ó Néill , Aodh Rua Ó Dónaill and other Irish clan leaders against English rule . Owing to Spanish involvement , and the strategic advantages to be gained , the battle also formed part of the Anglo - Spanish War ( 1585 - 1604 ) , the wider conflict of Protestant England against Catholic Spain . Background – The Tudor conquest of Ireland . Ireland had been claimed as a lordship by the English Crown since the 12th century but the actuality of this Lordship was only officially on paper as the reality on the ground was quite the contrary . The initial Anglo - Norman invasion starting in 1169 pushed deep into Ireland but ended up only as a partial conquest or draw . After this initial phase the Normans lost their steam and began to intermarry and form alliances with the leading native Gaelic families . Gaelic families began to regain their lost lands and Norman barons started to fight amongst themselves to vie for supremacy . By the 16th century , the area under government control had shrunk to the Pale , the area around Dublin . The rest of the country was controlled by the mini - lordships of clan and feudal leaders . King Henry VIII tried to reintegrate the territory of the country by recognizing the titles of the Irish nobility . The English throne initiated an official policy of surrender and re - grant . The aim of this policy was an attempt to assimilate and anglicize the Irish or turn Ireland English . Irish nobles were given English titles and legal charter to their lands under English law in return for submission to the Crown . This policy also included primogeniture , meaning the eldest child inherited all titles and power , ultimately becoming chieftain . This stood in stark contrast to the Irish or Brehon Law of Tanistry in which the most qualified was elected as chieftain by the clan . He also created the Kingdom of Ireland in 1541 , with himself as monarch . But whenever English officials tried to control the actions of Irish lords , they were invariably met with resistance . The English spent the next 50 years trying to exert their control over the Irish population , often by exceptionally brutal means . The first major conflict this caused was the Desmond Rebellions between 1569 and 1583 . In the 1590s they experienced the most significant resistance , from forces in Ulster under Aodh Mór Ó Néill ( Hugh the Great O ' Neill ) and Aodh Rua Ó Dónaill ( Red Hugh O ' Donnell ) . This war is known as the Nine Years War . It was a war of fort and forest . The English sought to establish frontier strongholds that would disrupt Gaelic rule . The Irish rebels used guerrilla tactics of ambush and constant missile harassment followed by withdrawal into the widespread forests . English armies seeking to relieve or supply forward garrisons suffered constant , and sometimes major , casualties . The battle of the Yellow Ford in August 1598 is the prime example where the English arguably suffered their greatest ever defeat on Irish soil . In an attempt to deliver supplies to a garrison in Armagh the commanding officer of the relief column , Marshall Bagenal , was killed along with over 20 officers and several hundred men . British forces were further reduced due to desertion and to disease conditions arising from the wet climate and poor nutrition . English fortunes hit their nadir with the humiliating truce negotiated by the Earl of Essex who had arrived in Ireland in 1599 at the head of 12 , 000 troops . His army melted away without fighting a single battle . What had started as a rebellion of Ulster Chieftains seeking to defend their ancient rights was drawing support from discontented lords throughout Ireland and grew into a struggle to end English rule . However , with the appointment of Charles Blount , Lord Mountjoy , as Lord Deputy of Ireland , the tide began to turn against O ' Neill . A new policy of favors for those willing to return to English allegiance coupled with the building of cleverly placed forts behind the Irish positions , such as that at Lough Foyle , increased pressure upon the Ulster Chieftains and stopped the advance of their cause . Earl Hugh O ' Neill , who had masterminded the Irish military success understood that while Irish troops were excellent at the hit - and - run tactics essential in a war of attrition , they would quickly be defeated in any formal battle . The new fortresses in his rear limited his ability to use hit - and - run tactics . Rival chieftains were always liable to return their allegiance to the English crown with suitable inducements . < Sean O ' Faolain , " The Great O ' Neill " Mercier Press > A war in stalemate could only end with English victory . Since 1591 , the Irish rebels had been seeking military help from Spain , and on September 21 , 1601 , in spite of bad weather , a Spanish landing finally materialized . The arrival was timely . The outcome of the war was in the balance and this Spanish force under General Don Juan Del Aquila had the potential to tip the fortunes of war in favor of the rebels . Further Spanish troops were promised . Spanish landing . Following the failure of the Spanish Armada in 1588 and the dispersal by storms of two more expeditions during the last years of Philip II , Phillip III decided to provide direct support ( material support had been sent for years ) to the Irish rebels fighting England . Spanish aid was offered to the Irish rebels in the expectation that tying the English down in Ireland might draw even more English resources away from their allies in the Netherlands , the Dutch Estates - which were engaged in a long rebellion against Spanish rule - and provide another base for privateers , such as the Dunkirkers , to disrupt English and Dutch shipping . Phillip sent Don Juan del Águila and Don Diego Brochero to Ireland with 6 , 000 men and a significant amount of arms and ammunition . Bad weather separated the ships and nine of them , carrying the majority of veteran soldiers and gunpowder , had to turn back . The remaining 4000 men disembarked at Kinsale , just south of Cork on 2 October 1601 . Another force commanded by Alonso de Ocampo managed to land at Baltimore . The Spaniards rushed to fortify precarious fortifications to withstand the approaching English armies . While the Spanish army had secured the town of Kinsale , they failed to expand their base into the surrounding region and were vulnerable to becoming besieged by English forces . On hearing of the Spanish landing , Charles Blount , Lord Mountjoy , the assigned Lord Deputy of Ireland , weakened the garrisons around the Pale and rushed to Kinsale with as many men as he could take , and laid siege to the town . English reinforcements were brought in through Oysterhaven , bringing the army ' s complement up to 12 , 000 . However many of these fell ill , leaving about 7 , 500 capable of fighting . At the same time , the Gaelic Earls Hugh O ' Neill and his ally O ' Donnell considered their positions . Their difficulty was that the Spanish had landed on the south coast of Ireland far away from the areas under control of the Irish Chieftains . In order to bring aid to the Spanish troops they would have to lead their troops into regions where support for their cause was most doubtful . They hesitated for weeks as autumn turned into a particularly wet and stormy winter . The besieged Spanish garrison began to suffer privation and O ' Neill was forced to go to their aid . He fully understood that should this first Spanish force suffer defeat he would be unlikely to receive further military help . < Sean O ' Faolain , " The Great O ' Neill " Mercier Press > The decision of the Spanish to land at Kinsale forced Earl Hugh O ' Neill to agree with his more impetuous ally , Red Hugh O ' Donnell , and abandon his hitherto successful hit and run tactics and risk open confrontation . A large force would be necessary ; larger than they could afford to lose . They set out on a 300 mile winter march - separately , to ease supply - with a total of 5 , 000 infantry and 700 cavalry . The combined armies of O ’ Neill , O ’ Donnell and Tyrrell came to 6 , 180 . This included 500 of Donal Cam O ' Sullivan Beare ’ s men , and 200 of Ocampo ’ s Spaniards . The siege . Lord Mountjoy ' s forces were incapable of surrounding the town of Kinsale and its surrounding area ( now called Belgooly ) , but they did seize some higher ground and subjected the Spanish forces to constant artillery fire . The English cavalry rode through the surrounding countryside destroying livestock and crops , while both sides called for allegiance from the population . O ' Neill and O ' Donnell were hesitant about leaving Ulster open to attack by marching south , especially given the lack of supplies for their troops . When they did set out they successfully cut English supply lines across the island and , by December , the shortage of supplies and the severe weather had begun to take a toll on the besieging army , with many dying of dysentery and the . Reinforcements arrived from Spain , and on 24 December 1601 English date : ( 3 January 1602 for the Catholic Irish and Spanish armies ) moved into position . In three columns - led by Richard Tyrell , Hugh O ' Neill , and O ' Donnell - they marched toward a night attack , but owing to a lack of coordination and possible arguments between the commanders , they had failed to reach their destination by dawn . The English scouts were aware of the troop movements and , after leaving a number of regiments behind to guard the camp and cover Kinsale , Mountjoy led his forces to meet the enemy at a ridge northwest of the town . O ' Neill controlled the ridge , and intended to fight for it , with support from Aguila , O ' Donnell , and Tyrell on multiple sides . Del Águila , the Spanish commander , was an experienced soldier and put up a fierce defense . His instructions were , however , to hold the town until the Irish army came down from Ulster to combine with them . When neither of his allies showed signs of movement , O ' Neill ordered a retreat into the marshes , hoping to mire the English cavalry in the soft land . In the end , the Irish were overpowered by the English cavalry , who charged through O ' Neill ' s men , and prevented a flanking maneuver by O ' Donnell . The tactics showed that the Irish Foot were poorly trained for open field fighting and the formation of the hollow square . It also showed up the English cavalry techniques using the lance , as compared with the Irish method of no stirrup and overhead spear throwing . The Irish army left the field in some disorder while the supporting Spanish army led by Ocampo tried to hold the charge and the ensuing massacre . Most fled back to Ulster , though a few remained to continue the war with O ’ Sullivan Beare and Dermot Maol MacCarthy Reagh . The Spanish , who lost many men in the siege , gave up the town to Mountjoy , " on Terms " and were allowed to sail back to Spain , not knowing that only a few days ahead another Spanish force was sent . Outnumbered , deprived from any enforcements and provisions and under constant English bombardment the Spaniards had held the town of Kinsale for more than 3 months . The English made no attempt to storm it . The Spanish were given honourable terms and surrendered Kinsale with their colours flying , and it was agreed that they were to be conveyed back to Spain on giving up their other garrisons of Dunboy , Baltimore , and Castlehaven . Another Spanish force was sent but never landed as news of Aguila ' s surrender was received they promptly turned back to Spain . Results . The English resumed their encirclement of the town of Kinsale , and after a number of days Del Águila sued for peace terms , which Mountjoy accepted . Del Águila saw his position as hopeless without the Irish lords ' effective action . This loss put an end to Spanish help in Ireland and to much of the Irish resistance . The Ulster forces returned to their home province , and after two more years of attrition the last of them surrendered in 1603 , just after the death of Queen Elizabeth . In the following year England and Spain agreed to make peace with the signing of the Treaty of London . O ’ Donnell went to Castlehaven and took a ship to Spain . He was well received there but died a few months later , said to be by poisoning by Carew ’ s spy , Blake . O ’ Neill returned to his native Ulster and then decided to go to Spain . He was accompanied by many supporters and other chieftains . This is known as the " Flight of the Earls " . Their intention was always to raise an army and oust English authority in their home province , but the territories they had left behind were soon divided up in the Plantation of Ulster , and they were never able to return . The English administration saw the ideal opportunity to seize most of the land of Ulster , and to bring in Presbyterian Lowland Scots and northern English settlers to farm it . The English had achieved their objectives of destroying the old Gaelic order , ridding themselves of the clan system and the more troublesome chieftains . The result of the Battle of Kinsale was devastating to the existing Irish culture and way of life , as the old Gaelic system was finally broken . As the Gaelic aristocracy fled to continental Europe , they left behind a power vacuum that the English eagerly filled .