On the morning of 14 September 1402 the raiding Scottish army on its return march to Scotland seemed unaware of the presence of the English force ahead of them. On leaving the town of Wooler they found their route blocked by the waiting English army. Moving to the left of the road the Scots took up position on the slopes of Homildon Hill. The English now moved around to face them, taking up position on the slopes of a hill opposite (probably Harehope Hill) deploying their archers on the flat ground to the fore. The rest of the English force remained in position on the plain below the hills.

The battle opened with an arrow-storm from the English archers wreaking havoc upon the Scottish schiltrons. The Scottish archers responded but their arrows fell short causing little damage to the English lines. The English archers fired relentlessly their arrows falling ‘like a storm of rain’. The Scottish archers withdrew and casualties amongst the unprotected Scottish spearmen quickly mounted. The ever eager Henry Hotspur Percy was keen to advance his main force but was advised by Dunbar to hold back and allow the archers to do their work. Whilst the Scots maintained this position they were being slaughtered. Unable to witness the loss of his army unopposed, Douglass led a charge down the hill directly into the maw of the English archers who gave ground but continued to fire. The headlong rush of the Scots was quickly halted, Douglas was badly wounded and captured, and the English archers now advanced, the arrows still coming so thick and fast the Scots were smothered and made ‘bristly like a hedgehog’ their hands and arms transfixed to their own lances. The Scottish armour was no match for the English arrows, even Douglas’ elaborate armour was pierced five times.

A further charge down the hill was now led by Sir John Swinton who exhorted the Scottish troops to join in hand-to-hand combat rather than stand and be slaughtered as beasts in a pen. It is unclear from the sources where this charge was made but it is likely that it was against the troops of Percy and Dunbar arrayed on the level ground between the hill and the River Glen, who had so far taken no part in the action. Swinton's charge was as ill-advised as Douglas’, and within an hour the battle was over with many Scottish dead and still more fleeing the field.