Percy’s forces arrived at Otterburn in the evening of 19th August 1388 footsore and weary after a day’s march of some 30 miles in hot summer weather. The unsuspecting Scots had settled down for the evening, the nobles, having donned loose gowns in the heat, ‘for the hete tuk on syd gownys’ prepared to attend to no more than their evening meal. The arrival of a scout with the news that the enemy was upon them caused disorder and panic as they rushed to arm themselves; the Earl of Moray forgetting his basinet (helmet) in the confusion.

Percy was not so hot-headed that he rushed into combat without consideration. Assessing the Scottish position, Percy sent a detachment under Thomas Umfraville (although sources dispute who led the flanking movement) to swing around the Scottish positions and attack the camp from the rear. Percy, meanwhile, launched a direct attack on the Scottish main force. Fierce and bloody battle ensued under moonlight along a ridge stretching from the River Rede in the south up to the slopes where the Percy Cross now stands. The English initially made headway but it was at this point that Douglas made his planned counter-attack; for although the Scottish commander had been caught unawares by Percy’s unexpected arrival he had, nethertheless, made plans as to how to tackle the English forces once they did arrive. An unexpected night-time battle did not alter his plans, indeed the cover of night probably assisted his manoeuvres. Douglas led a detachment in a wide arc on his left, charging down the slope to attack Percy’s right flank.

Douglas’ and Umfraville’s flanking movements were on the same side of the battle i.e. the Scottish left and the English right. Umfraville could not have advanced on the Scottish right due to the extensive boggy land in that direction; which was no doubt deliberately chosen by Douglas for that purpose. But by some chance the two flanking detachments missed each other; one swinging wide of the other, and each arrived unhindered to their destination. Umfraville found an almost deserted camp and quickly took control. After waiting for some time, although what for is unclear, he left a small guard on the camp and advanced towards the sounds of battle.

Douglas’ flanking attack was ultimately successful, for although fierce hand-to hand fighting continued for some hours the English were gradually forced into a tighter and tighter section of the field. Unable to use their longbows, tired and hungry, the physical superiority of the rested and fed Scots began to tell. Douglas was fatally wounded but his condition was hidden lest it give dismay to his own troops and courage to his enemies. During the course of the night Henry Percy and his brother Ralph, along with other English nobles, were captured and in the light of morning the Scots held the field.