at Kilchummin in the Great Glen, with supplies exhausted and with his forces reduced to less than 2,000 due to sickness and desertions amongst the Highlanders, who were eager to return home with their plunder. At Kilchummin he learned that a large contingent of Northern Levies under the Earl of Seaforth blocked the route northward at Inverness, while Argyll – with a force made up of his own regiment, eight companies of Lowland foot sent by Baillie, and a large number of Clan Campbell levies – was camped to the south of him at Inverlochy. Further south, Baillie and Sir John Urry were assembling further troops. The Royalists were now effectively trapped. The flank march Montrose decided to face the threat by marching south and attacking Argyll. This course may have been chosen as Argyll's men now threatened the lands of several of Montrose's key supporters. However, he realised that a frontal approach would be quickly detected. What followed was a remarkable flanking march, during winter, across some of the toughest and wildest terrain in the British Isles, partly through snow knee-deep. The Royalists first travelled up the River Tarff to Glen Buck via Culachy, and across the gorge of the Calder Burn to reach the head of the glen, 1000 feet above sea level. They then climbed a further 1000 feet to Carn na Larach, before travelling down Glen Turret and Glen Roy to Keppoch, where the advance guard rested for around three hours in a barn while the main force caught up. After fording the Spean, and passing through Leanachan Woods, they emerged on the slopes of Ben Nevis above Inverlochy in the early hours of Candlemas Day, 2 February; they had marched around 36 miles in 36 hours. The battle Montrose's army spent a cold night in the open on the side of Ben Nevis. Argyll was already aware that a small force was operating in the area, having been alerted by pickets driven from Keppoch by the Royalist advance guard. He did not know, however, that he was faced by the entire royal army. Just before dawn on 2 February 1645, Argyll and his commanders were dismayed at the sight that lay before them. As far as they were aware Montrose should still have been 30 miles north. Order of Battle and deployments Royalist (James Graham, 1st Marquess of Montrose) Irish Brigade Alasdair Mac Colla Thomas