The accession of strength which the cause of liberty acquired, by the prudent measures of our patriot, enabled the Scots more effectually to embarrass the movements of the enemy. While he, with his brave followers, continued to surprise the foe, by breaking into their camp where least expected, the other leaders were engaged in preventing supplies from reaching the English; and Edward, at last, became apprehensive of advancing too far into the sterile regions of the North. A scarcity had already begun to be severely felt in his army, and he now prudently directed his march towards the more fruitful districts in the neighbourhood of Perth. But there also his unwearied and restless enemy continued to assail those parts of the army that appeared most vulnerable; and having at last cut off a part from the main body of the English forces, by breaking down the bridge over the Tay, in three successive engagements he defeated them with great slaughter. The English army, however, was still too numerous for the Scots to risk a general engagement; and Edward, finding no probability of bringing the war to a satisfactory conclusion, after wreaking his vengeance on the most fruitful parts of the country, returned home through Ayrshire and Annandale, carrying with him all the spoil he could collect. A body of troops under the command of Henry de Lacy, made a similar inroad in Fife, destroying whatever came in their way, in revenge, no doubt, for the gallant stand the inhabitants had made under MacDuff, their late unfortunate chief. After destroying St Andrew’s,[30] he laid siege to the castle of Cupar, which surrendered about the end of July.[31]