The main body of the Royalists was encamped on Philiphaugh, a long and level meadow on the left bank of the Ettrick, immediately below its junction with the Yarrow. Behind rose the hills; in front ran the river; at the western end the ground sloped upwards to a wooded declivity known as Harehead-shaw. This strong position had been still further secured by some trenches hastily thrown up on either flank. Here lay the Irish infantry, with the country levies horse and foot, less than two thousand strong in all. But by some strange infatuation Montrose had fixed his own quarters in the town on the opposite bank of the river with the best part of the horse and all his principal captains. His little army was thus divided in half, and his men separated from their officers, at the moment when the bravest and most skilful foe he had yet encountered was creeping on him through the darkness at the head of a force more than four times his strength. It is not surprising that Montrose should have been ignorant of Leslie's change of route when we remember that he was in the midst of a population bitterly hostile to himself and his cause. But that his own scouts should have suffered so large a force to advance unobserved within a mile of his lines is indeed inexplicable. If it be true, as one account reports, that they were mostly Traquair's tenants employed on this service as familiar with the country, the explanation is found. Wishart confesses that Montrose, whose custom had always hitherto been to post his own sentinels and give his own orders to his scouts, on this night left the duty to his officers, being busy with despatches for the King. The duty may have been negligently performed; the quarter from which Leslie was advancing may have been inefficiently patrolled, or even left altogether open. The night was dark and the morning misty. But even had the mist been thick as that which shrouded the "last, dim, weird battle of the west," it is not in the course of nature for four thousand horsemen and two thousand foot to draw within a mile without signifying their approach to the most careless ears. It is hard not to believe that there were some men abroad on the morning of the 13th, either in Selkirk or on Philiphaugh, who were aware of Leslie's advance. No excuse will serve to acquit Montrose and his officers of grave negligence; but only treachery can make intelligible the extraordinary and overwhelming suddenness of Leslie's attack.[19]