This important battle was fought on 14 August 1598 between the Gaelic native Irish army under the leadership of Aodh Mor O Neill and Aodh Ruadh O Domhniall and a crown expeditionary force under the command of Henry Bagenal, marshal of Ulster. The battle took place some two miles outside Armagh near the river Callan on the route to the river Blackwater.
In 1597, Lord Burgh had erected a fort on the Blackwater, the boundary between counties Armagh and Tyrone. The Blackwater fort was intended to facilitate later military penetrations into Tyrone, particularly to Dungannon, the stronghold of ONeill. Soon after it was built, it was besieged by the Irish. In 1598, it was still occupied but was running very low on supplies. There was a faction in the Dublin government who advocated the abandonment of ” the scurvy fort ” but the local commander, Marshal Bagenal, a bitter opponent, rival and brother-in- law to ONeill volunteered to lead the relieving force. A substantial army of some 4000 troops was mustered at Ardee and advanced to the garrison town of Armagh. This force was well equipped with Musket and pike and had substantial supplies and also artillery including a heavy demi-cannon drawn by a team of Oxen.
ONeill, who had an excellent intelligence network, was fully aware of the force that was being sent against him. He called on his ally Aodh Ruadh ( Red Hugh) for assistance and he personally, led a substantial force from Donegal and Connaught to the area. Most of the Ulster Clans sent men to ONeill and of course he had his own mercenaries from other parts of Ireland and from the Scottish Highlands and Isles. It is estimated that he had a marginally larger force than the Crown. Prior to the arrival of the English army ONeill, who had English and Spanish military engineers within his ranks, dug trenches at strategic spots along the route to the fort and plashed pathways with interlaced branches and felled trees. They also set up black thorn breast-works to facilitate ambushes and to slow down the horses and men of the advancing expeditionary forces.
Bagenal arrived in Armagh on the 13th and set up his H.Q. at the old cathedral, whist his main force camped on a hill just outside Armagh. His scouts advised him of the potential for ambushes along the main road, on the left bank of the Callan river. He knew the country well and he was supremely confident of the superiority of his forces and their weaponry. In a head-on contest, the English army would, as usual, win the day.
Early on the morning of the 14th, the Marshal crossed the river Callan at a ford just outside Armagh and moved up the right hand side of the river thus avoiding the prepared ambushes, although they were constantly fired on from across the river. The Crown forces were organised in six regiments, two forward, two centre, and two rear, with the cavalry at the centre. An experienced commander would know that in the march, this formation must be maintained with proper distances between the regiments so that they all maintained constant contact. ONeill’s objective that day was to harass the moving army to slow it up and disrupt the regular formation. This was to be achieved by ambush and sniper fire. However he was to be greatly assisted by an area of soft boggy terrain on the path chosen by Bagenal. Although the English had brought brush-wood matts to facilitate the crossing of soft ground they had apparently not anticipated the difficulty of crossing it with the heavy ordinance and supply wagons whilst being under constant, probably accurate fire, from the Irish. This caused the distance between the forward regiments and the rest of the column to increase and become isolated. The first forward regiment had pushed on to the first Irish trench and after heavy fighting succeeded in crossing it only to find that they were in a prepared killing zone and they were forced to retreat into the path of the regiment following. At this point, near the place now known as Bagenal’s bridge, the marshal was killed by a bullet to the head. The command was taken over by Thomas Maria Wingfield but shortly after this the gun powder store ignited, apparently accidentally, causing further confusion and demoralisation. Wingfield started to organise a retreat to Armagh but the commander of the forward section, called Evans, didn’t retreat and ONeill taking advantage of the enemy confusion sent in his cavalry backed with swordsmen on foot and slaughtered this forward section at a place called the yellow ford from which the battle gets its name. The remainder made their way back to the relative safety of Armagh harried all the way by the Irish, who besieged the town.
The records of casualties on the Irish side are very scanty, but casualties were relatively light, perhaps 200 to 300 killed. Crown forces lost about 900 killed and this included 18 officers. Several hundreds of the Irish soldiers in the English army crossed over to ONeill and many hundreds deserted and just ran off. Out of the 4000 soldiers who had left Armagh that morning, about half returned. The following day, the cavalry broke out and fled to Newry. After three days negotiations with the Dublin administration, the Crown forces were permitted to leave Armagh without their weapons, as was Captain Williams and the Blackwater fort garrison.
The immediate outcome of this battle was to increase the prestige of ONeill throughout Ireland and Europe. Many who had avoided becoming involved now joined the Gaelic alliance. It increased Queen Elizabeth’s determination to defeat ONeill and complete the conquest of Ireland and to this end she substantially increased the size of her army and equipment in Ireland. Thus the outcome of the battle was to leave ONeill with no room for negotiation with the Queen and an escalation of the nine years war.