Edward at once summoned his army to muster at Newcastle by the second week in June; but early in May he postponed the assembly till July 24. By that time, however, the Scots had completed another destructive raid. Before mid June, a force had crossed the western March; and in the beginning of July, Robert himself, with Randolph and Douglas, penetrated beyond Preston and ravaged the length and breadth of Lancashire and the archdeaconry of Richmond, burning Lancaster town and castle 'so entirely that nothing is left,' and carrying off what cattle had not been driven for safety into the remoter parts of Yorkshire. They do not seem to have encountered local opposition. As they returned, they lay five days before Carlisle, without drawing forth the prudent Harcla; and on July 24, they struck their tents for home. The English army followed them, entering Scotland by the eastern March in the first days of August. Robert withdrew both men and cattle from the Merse and the Lothians, either to the strongholds or beyond the Forth, and lay with his army at Culross. Barbour tells how an English foraging party found but one lame cow at Tranent: 'It is the dearest beef I ever saw yet,' remarked Warenne, 'it must have cost £1000 and more.' Edward himself subsequently wrote that he had 'found neither man nor beast' in the Lothians. The English fleet failed to bring up provisions, and, on August 23, Edward found himself with some 7000 men at Leith, in like predicament with his father before the battle of Falkirk. He was starved into retreat. Immediately the Scots hung upon his rear, and Douglas cut up an advance company of 300 men near Melrose. The English had sacked Holyrood; they now sacked Melrose Abbey, killing the prior and others; and they burnt to the ground Dryburgh and other monasteries. 'But,' says Fordun, 'God rewarded them therefor.' Bruce instantly followed up his advantage. By the middle of September, the Scots were before Bamborough and Norham. Bamborough bought off the invaders; and on September 26, Sir Roger de Horsley, the constable, as well as the constables of Warkworth, Dunstanburgh, and Alnwick castles, received a severe wigging from Edward for not showing fight against such an inferior force. Norham was defended by Sir Thomas Gray the elder against an inadequate body of 200 Scots. Edward displayed great energy of rebuke and counsel, while Robert steadily advanced southwards. On October 14, the English army barred the way on the ridge of Blackhowe Moor between Biland and Rievaulx; but Bruce's rapid action enabled him to strike a decisive blow before the Earl of Carlisle, who was at Boroughbridge with 2000 (surely not, as some say, 20,000) horse and foot, could effect a junction, if indeed he really meant to do so.