The Battle of the Yellow Ford is fought in western County Armagh, near the River Blackwater on August 14, 1598, during the Nine Years War. It is fought between the Gaelic native Irish army under Hugh O’Neill, Earl of Tyrone, and Hugh Roe O’Donnell and a crown expeditionary force from Dublin under Henry Bagenal. The crown forces are marching from Armagh to resupply a besieged fort on the Blackwater when they fall into an ambush and are routed with heavy losses.
The crown forces are organized in six regiments — two forward, two centre, and two rear, and with cavalry at centre. As soon as they leave Armagh garrison, they are all harassed with gunfire from rebel forces concealed in the woods. As a result, the different regiments become separated from one another as they pause to deal with the hit and run attacks. The problem is accentuated when one of their ox-drawn artillery pieces becomes stuck in the bog with a damaged wheel and a rear regiment stays behind to guard it as it is slowly coaxed through the bog. The regiment at the front of the march encounters a mile-long trench, 4 feet wide and 5 feet deep. The regiment succeeds in crossing the trench but then comes under heavy attack from large forces and decides to retreat back across the trench, suffering significant losses during the retreat. This regiment then merges into the ranks of the other forward regiment.
At this point, Henry Bagenal is killed by a shot through the head. Command of the army is assumed by Thomas Maria Wingfield. Further demoralising the crown troops and causing chaos, their gunpowder store explodes, apparently ignited accidentally by the fuse of a matchlock musket. Daunted, Wingfield decides to retreat to Armagh. The commander of the forward part either doesn’t get the command or refuses to obey it, or is unable to execute an orderly retreat and judges it necessary to maintain his forward position. Seeing their enemy in confusion, the O’Neill cavalry rushes at the head of the forward part, followed by swordsmen on foot. Crown troops in this part of the field are cut to pieces and any wounded left on the field after the battle are slain as well. The rest of the crown forces have to struggle their way back to the Armagh garrison. They reach it largely intact, but are harried all the way by the Irish.
Crown forces lose approximately 1,500 men in the battle, including 18 “captains” or officers. Three hundred soldiers desert to the rebels including two English recruits. Out of 4,000 soldiers who set out from Armagh, just over 2,000 reach the town after the battle and become virtual prisoners inside. The cavalry breaks out and dashes south escaping the Irish.
After three days of negotiations, it is agreed that the crown troops can leave Armagh as long as they leave their arms and ammunition behind and that the garrison of the Blackwater Fort surrenders. O’Neill’s forces suffer perhaps 200 to 300 casualties in the battle, though sources for the number lost on O’Neill’s side are very scanty. In light of the battle’s outcome, the court at London greatly and rapidly increase its military forces in Ireland. Simultaneously, many in Ireland who have been neutral on the sidelines begin to support the rebellion. Thus the ultimate outcome of the battle is an escalation of the war.