The English force that marched out from York's gates was no army. It was the citizens of the city, the choristers of the Minster, monks from local houses, and clergy of every rank, all pressed into service under the archbishop because no other defenders were available. The number who marched is uncertain. The chronicler John Barbour gave the English losses as a thousand killed, three hundred of them priests, but contemporary numbers are notoriously unreliable. What is certain is that the army that left York carried sacred banners, that many in its ranks had never held a weapon, and that they were marching toward soldiers who had fought through the Scottish wars of independence for two decades. The Brut Chronicle, the fullest contemporary source, describes the encounter with a kind of stunned brevity.

Three miles east of Boroughbridge, at Myton-on-Swale, where the rivers Swale and Ure meet, Douglas and Randolph waited. Their men formed schiltrons, the dense formations of spearmen that had broken English cavalry at Bannockburn five years earlier. Schiltrons were not subtle. They were a wall of points, slow to move but nearly impossible to break with infantry. The English clergy and townsmen, with no training in formation fighting, advanced through the marshy ground between the rivers. The Scots had also set fire to nearby hay, sending smoke drifting across the field to disorient the approaching force. When the two sides met, the schiltrons held, and the white-cassocked clergy bunched against them died in their hundreds. Many drowned trying to flee back across the Swale.

The encounter took its nicknames from what the dead looked like and who they were. The number of cassocked clergy among the casualties was so striking that contemporaries called it the Chapter of Myton, using the term for a formal meeting of canons or monks. It was also called the White Battle, after the white vestments and robes worn by many of the dead. Among those killed was Nicholas Fleming, the Mayor of York. Archbishop Melton himself escaped, though contemporary accounts hint at considerable embarrassment about how. Edward II's queen Isabella had been evacuated from York the day before the Scots could reach the city. The raid had failed in its immediate aim, but its real purpose, drawing English attention away from Berwick, succeeded completely.

News of Myton reached the English army outside Berwick within days, and the consequences were exactly what Bruce had hoped for. The northern English nobles, led by the Earl of Lancaster, refused to remain at the siege while their estates burned. The king and his southern lords wanted to press on. The army fractured. Lancaster withdrew. The siege had to be abandoned. Rumors spread, possibly true, that Lancaster had been in secret communication with the Scots, since his lands had been conspicuously spared by Douglas's raiders. Hugh Despenser, the king's favorite, accused Lancaster of treason for having tipped off the Scots about Isabella's location. The whole 1319 campaign collapsed into recrimination, and Edward was forced to ask Bruce for a truce. It was granted just before Christmas.

Myton-on-Swale today is a tiny North Yorkshire village. The confluence of the Swale and Ure still flows past flat fields of pasture and arable, with no visible sign of what happened here on a September day seven hundred years ago. Edward II's reign would end in deposition and a violent death in 1327. Robert the Bruce died of illness in 1329. The Wars of Scottish Independence eventually wound down, and the Treaty of Edinburgh-Northampton in 1328 finally recognized Scottish independence under Bruce. The Chapter of Myton receded into the footnotes of medieval history, but the place stayed registered as a historic battlefield in England. The bones of the clergy and townsmen who marched out of York that morning lie somewhere under the soil of the river meadows.