But in the course of the same autumn, and before the arrival of Godfrey, the lives of William and his family were threatened by an unexpected danger from a totally different quarter. The king, with his brother and the prince of Scotland, was staying with the court at Perth, when a sudden inundation, occasioned by a spring tide meeting the swollen waters of the Tay, menaced the town and its inhabitants with destruction. The old hill-fort at the junction of the Almond with the Tay was swept away in the deluge, carrying along with it many houses, and destroying the bridge and an old chapel, whilst the royal party were at one time in imminent danger, escaping with difficulty the fury of the flood.[499] [Sidenote: A. D. 1211] It was winter when Mac William arrived in Ross, and six months elapsed before an army could be dispatched to operate with effect against him, the king following by easy marches, as well as his debilitated condition would allow. Each party pursuing their usual tactics, the campaign was opened on the royal side by the construction of two forts, or rather, perhaps, by the repair of the buildings, which had been raised in the previous war to command the most important points in the district;[500] whilst Godfrey, carefully avoiding a battle, endeavoured to harass the royal army by continued surprises and night attacks. Steadily pursuing the course which he had proposed to follow in his campaign against Donald Bane, the king placed 4000 men under the command of the Earls of Atholl and Buchan, with Malcolm of Mar and Thomas the Durward, ordering them to penetrate the recesses of the mountains in every direction, and force Mac William to an encounter. Godfrey’s place of strength was upon an island, where he had collected his treasure and supplies; and here he was at length discovered and brought to bay by the royal leaders. The struggle was most obstinate, for the rebels were animated by despair; victory, however, declared for the royal arms, Godfrey with a few of his companions escaping, though with difficulty, amongst the clefts and thickets of the neighbouring mountains.[501] Satisfied with his success, William returned with the main body of his army to the south, leaving Earl Malcolm of Fife in charge of Moray. His departure was the signal for the reappearance of Godfrey, who suddenly presented himself in force before one of the royal castles, and commenced preparations for a siege. Alarmed at the prospect of an attack, and the probable consequences of its success, the garrison offered to capitulate on condition that their lives were spared; and as Godfrey willingly agreed to their terms, they were permitted to depart in safety, and the fort was burnt to the ground.[502] [Sidenote: A. D. 1212.]