During the winter of 1315-16 Berwick was under siege by the Scots, the garrison facing starvation. On St Valentines day 1316 a Gascon ,Raymond de Caillau, led a squadron out of Berwick on a foraging raid. They captured cattle and food as well as taking hostages from the Merse. Douglas, warned of what was afoot, set off to intercept this raiding force.

Douglas intercepted the English force at a ford on the Skaithmuir near to Coldstream. The English, from Berwick, when they saw how few men Douglas had with him disbanded their defensive schiltrom and went onto the attack. After a hard fight, which Douglas later claimed to be the hardest he had ever known, most of the Berwick men were slain, Raymond de Caillau by Douglas's own hand. A report by Maurice de Berkeley, the keeper of Berwick, four days later put the number of missing at twenty men-at-arms and sixty foot. Unfortunately we do not know the strength of Douglas's force at the time only that it was numerically inferior.