By the spring of 1643, the Crown forces in Ireland were in a desperate condition. Only twelve months earlier, the Irish insurgents had seemed to be on the brink of defeat, losing the important battles at Kilrush and Liscarrol. As during the Nine Years War four decades before, the English had put into action a scorched earth policy to cripple the insurgents: starvation and famine were recognised throughout Europe as a brutally effective stratagem of bringing rebels to heel.
The circumstances this time, however, differed markedly from those in the 1590s. By September 1642 England had descended into Civil War. The leaders of the Crown forces in Ireland realised, too late, that their tactic of scorched-earth was ultimately self-destructive. British supply ships that had previously succoured the soldiers of the Crown armies were needed back home, and the supply of munitions and victuals from Britain fell to a trickle. Agriculture in many regions of Ireland had been devastated, so there was little relief from that quarter. Essentially, the Crown army in Ireland now found themselves in the same boat as the Irish Insurgents.
The shortage of food invariably led to outbreaks of disease. Hundreds of the English soldiers garrisoning the strategically important town of Athlone died of dysentery and starvation, and subsequently withdrew to Athboy. The town was then occupied by Irish Confederate troops. The difficulties of the Crown forces afforded the insurgency enough breathing space to co-ordinate their political and military effort. Regular provincial armies were organized, as was a system of taxation and supply.
Murrough O'Brien, the Baron of Inchiquin and leader of the Munster Protestant forces described his condition as desperate in a letter to Parliament in May 1643. In truth, his forces seem to have been in a better shape than those of the other regions of Ireland, having by then taken control of most of the towns of the province of Munster. Killamock, a central Munster town located almost exactly halfway between the chief Munster Cities of Limerick and Cork, was Inchiquin's next target. The capture of this town would allow the Protestant army to expand their quarters and increase their food supply.
The Supreme Council of the Irish Confederacy in Kilkenny were alarmed by this development. The General of the Irish Munster army was Garret Barry, a highly experienced veteran of the Wars in Europe, but a man whose reputation was under a cloud since being beaten by Inchiquin's forces at Liscarrol the year before. As a result, the Supreme Council offered the Lord of Castlehaven the commission to command the Munster forces. Having received the commission, Castlehaven mustered eighty horsemen, as well as his own forty strong lifeguard of horse. This 120 strong force marched to Cashel to rendezvous with General Barry and Lieutenant-General Purcell. At Cashel he met another 120 horse of the Munster army, as well as seven hundred foot. The troop of Munster horse seem to have consisted mostly of mounted teenagers, for Castlehaven refers to them as 'boys'. The entire force that was assembled was now around 1,000 strong, including the squadron of light horse.
Inchiquin was preparing to besiege the town of Killamock when he recieved word of the Confederate approach. Having no stomach to risk his undersupplied force in battle, Inchiquin led most of the force he commanded westwards into Kerry, where the rugged terrain and unpredictable weather offered good protection to even a half-spent army. Before retreating he instructed Charles Vavasour, with a 1,600 strong force including some of the best horse and foot of the army, to take a strongplace known as Castle Cloghlea, a stronghold of the Condon family. Vavasour successfully pressured the castle to surrender, after which the stronghold was plundered by the troops. Thirty-eight men, women and infants found sheltering inside were stripped of their clothing, and then put to death. The soldiers of Inchiquin's army were brutal at the best of times, but in the desperate circumstances they were in, even less mercy than usual could be expected. In this one instance, however, Inchiquin's men would quickly pay a high price for their ruthless conduct.
The Irish Confederate armies generally contained only a small number of horse compared to foot, and this put them at a major disadvantage. Ostensibly, the reason for the small number of horsemen was because footmen were cheaper to equip and maintain than horse, but as Lenihan has noted, it was a case of false economy, given that horsemen were much more likely to escape from a battlefield in the event of a defeat (furthermore, they were also more likely to retain their weapons and equipment, as fleeing footmen would just throw their cumbersome weapons away).
The victory at Castlelyons highlights the importance of horsemen in 17th century warfare in Ireland. The victory was purely a cavalry victory, due in part to Castlehaven's knowledge of the terrain and also- as will be argued further below- the weapons used by the Munster horsemen. Castlelyons would prove to be the only major Irish field victory of either the Leinster or Munster armies (the victorious army was composed of elements of both these Confederate armies), at least against a Protestant force.
At Castlelyons, the decisive moment for the Irish was the rout of the enemy horse. The Cork Protestant army under Vavasour had comparable numbers of horsemen as the Irish force under Castlehaven, and it would seem that differences in weapons between the horse-soldiers of both armies played a part in the outcome of this Cavalry engagement.
The Horseboys of Ireland
Lenihan, in his work on the Irish Confederate Wars, states the battle occurred near the castle of Cloghlea. This would seem to be at odds with the account of the battle by Castlehaven, who, in his memoirs, states that the battle took place on a large plain in front of Castlelyons. Possibly, Lenihan may have sited it in the environs of Cloghlea due to a misreading of C P Meehan's 19th century account of the war.
A second battle was fought near Castlelyons in 1646.
Tuchet, James(1682). The Memoires of James Lord Audley, Earl of Castlehaven
Meehan, C.P (1882). Confederation of Kilkenny.
Nicholls, K.W (2003). Gaelic and Gaelicized Ireland in the Middle Ages, Lilliput Press, Dublin
Lenihan, Padraig, (2001).Confederate Catholics at War, Cork University Press, Cork