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. The local commander, Marshal Bagenal, a bitter opponent, rival and brother-in- law to ONeill volunteered to lead the relieving force.
ONeill, who had an excellent intelligence network, was fully aware of the force that was being sent against him. 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.
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. 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. 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.
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.