Barbour, making no mention of these exploits, brings Bruce north of the Mounth and on to Inverurie in Aberdeenshire. Bruce is joined by Sir Alexander Fraser and Simon Fraser—the famous Sir Simon's brother and son—who had apparently been acting in his interests in the north, opposed mainly by Comyn (Earl of Buchan), Sir John de Mowbray, and Sir David de Brechin. At Inverurie Bruce fell very sick. He could neither eat nor drink; no medicine did him any good; he became too weak to ride or to walk. Sir Edward Bruce, says Barbour, tried to comfort the men, but it seems much more likely that Sir Edward remained in command in Galloway, while Douglas made excursions towards the eastern border. At any rate, Bruce's men would not fight while their chief was ill, or Bruce had too much prudence to allow them; so they placed him on a litter and carried him into the Slevach (mountain fastnesses). Comyn, hearing of Bruce's serious illness, advanced against him with Mowbray and Brechin, and with a largely superior force. The time, says Barbour, was 'after Martinmas, when snow covered all the land.' Bruce quietly awaited attack. On three successive days there occurred skirmishes between bodies of archers, Buchan's men getting the worst of the encounter day after day. Buchan's force, however, was continuously obtaining additions, while Bruce was getting pinched with hunger. Placing the King in his litter again, Bruce's men changed quarters, marching slowly in fighting order, with their sick chief in the centre, and restricting themselves rigidly to defence. They took up a position in Strathbogie, a little further north, and Buchan's force abandoned the pursuit and dispersed.

The King gradually regained strength and returned to Inverurie, 'to be in the plains for the winter,' for the better chances of food. Again Buchan proceeded to attack him, reaching Oldmeldrum 'on the evening before Yule even' (January 4) 1307–8, with about 1000 men. Next day Brechin made a dash at Inverurie; whereupon Bruce, in spite of remonstrances, determined to mount and fight, though, says Fordun, 'he could not go upright, but with the help of two men to prop him up.' He is said to have had 'near 700 men.' He advanced towards Oldmeldrum, and as the enemy retreated, pressed steadily upon them, pushing their retreat into flight, and pursuing them, Fordun says, as far as Fyvie. Buchan and Mowbray fled to England, while Brechin stood a siege in his own castle of Brechin. Bruce's 'herschip' (harrying) of the district of Buchan is said to have been so exemplary that men lamented it for half a century afterwards.

There are discrepancies between Barbour's account and Fordun's. Fordun dates Buchan's retirement from the Slevach on Christmas day (on which Barbour fights at Inverurie and Oldmeldrum), and he arranges a truce on the occasion. It is in the Slevach that he makes Bruce's illness commence. He dates the battle of Inverurie, without mention of Oldmeldrum, vaguely in 1308. He also calls Mowbray Philip, not John, and he says nothing of Brechin. Buchan and Mowbray, if they did not then flee to England, at any rate went south not very long after this time; and if Brechin surrendered his castle, it was certainly not, as Barbour says it was, to David, Earl of Athol, who was on the English side. On May 20, 1308, Edward writes to thank a great number of his officers in Scotland, including Athol, Buchan, Brechin, John de Mowbray, and others, for their faithful service, and he requests Buchan to remain 'in the district committed to him' till August 1. This may mean that up to May he had remained in command in the north, though keeping clear of Bruce's devastating track.

Having reduced the country beyond the Grampians ('benorth the Mounth'), Bruce descended upon Angus. Barbour says nothing of an attack on Brechin Castle, having already recorded its capture and the submission of Sir David to Bruce; but, as we have seen, Sir David was still—and, indeed, for several years to come—on the English side; and Barbour was evidently misinformed. Forfar Castle was taken by Philip the Forester, of Platter; the watch had not been vigilant, and Philip scaled the walls. Bruce demolished the castle; whether because it was of the old ineffective type, or because he had no means of holding it. He then, according to Barbour, invested Perth, which was strongly fortified, and was held by Moffat and Oliphant—Sir William Oliphant, the gallant defender of Stirling, who had been released from the Tower on May 24, 1308, having lain rusting there for nearly four years. The Earl of Strathearn, says Barbour, was also in the garrison, while his son and his men were in Bruce's camp; but Barbour is mistaken, for though Strathearn had been transferred from Rochester Castle to York Castle in the preceding November, he does not appear to have been released till November 18 of this year. Frequent skirmishes took place during a six weeks' siege, when Bruce suddenly decamped, amid the premature jeers of the garrison. After eight days he returned suddenly in the night, and, finding the English lulled in security, plunged into the moat up to his neck, mounted the walls by ladder, and surprised the sentinels. His men, dispersed in groups, gave the garrison no chance to marshal for effective defence. The English leaders were taken; but few men were slain, in consideration of their decent treatment of Scots. There was much booty for the victors. Bruce demolished the walls and the towers. 'Was none that durst him then withstand.' Whether this capture of Perth be fact or not—and probably it should be placed at a later date—Bruce now had the upper hand north of Forth.

While Bruce was re-conquering his kingdom in the north, Edward II. had married Isabella of France at Boulogne on January 28, 1307–8, and had been crowned at Westminster on February 25. He had at once plunged himself in difficulties with his barons by his infatuation for Piers de Gaveston. In June some purpose of accommodation with Bruce appears to have been pressed upon the English king. There exists a memorandum dated June, without the year, which Mr Bain rightly, it seems, assigns to 1308. It sets out that the levies summoned to meet the King at Carlisle on August 23 shall be countermanded; and that the King shall take no truce or sufferance from Bruce, but the Wardens of Scotland—Sir Robert de Umfraville, Earl of Angus, and Sir William de Ros of Hamelake (appointed on June 21)—'may take such, for as long time as possible, as they have done hitherto of their own power or by commission, so that the King, however, may furnish his castles with men and victuals, and that no one be taken or other "mesprision" made during such truce.' Then the wardens of districts are arranged. The Earl of Buchan, Sir John de Mowbray, and Sir Ingram de Umfraville are to be wardens of Galloway, Annandale, and Carrick respectively; Sir Alexander de Abernethy, Sir Edmund de Hastings, and Sir John Fitz Marmaduke, are to be wardens beyond the Forth. The endorsement bears that the Wardens of Scotland shall 'take truce from Robert de Brus as from themselves, as long as they can, but not beyond the month of Pasques' (April), and—curiously enough—that 'the King may break the truce at pleasure if the others will yield this point, but, if they will not, the truce may be made without it.' The memorandum testifies to the strength of Bruce's hold on the country, and to the recalcitrance of Edward's barons. Still Edward struggled on. On June 21, he requested a large number of officers to retain their posts till specified dates, and to join the Scottish expedition at Carlisle on August 23. On July 10, he requisitioned ships and men from Shoreham all round to Bristol, for the King 'needs a great fleet.' But on August 11, he countermanded the order for these ships and men, 'the King having deferred his expedition for the present.' The English barons were too strong for the young King.

It is not clear at what date Bruce proceeded to reduce Argyll. Probably, however, he undertook the expedition immediately after the reduction of the north. If he conducted a six weeks' siege of Perth, and Sir William Oliphant was one of the defenders, he could not have been free to go west till the very end of July 1308. Fordun states that, within a week after August 15, Bruce defeated the men of Argyll and subdued the whole land; that he then besieged Alexander of Argyll 'for some time' in Dunstaffnage Castle (some three miles from Oban); and that Alexander, on surrendering, refused to do homage, but was allowed a safe-conduct for himself and his followers to England. Barbour tells how Lorn—John, the son of Alexander—gathered some 2000 men and opposed Bruce in a narrow pass between a steep mountain and the sheer bank of a loch—perhaps between Ben Cruachan and Loch Awe. Lorn held the loch in his boats, and ambushed a party on the ridge commanding the pass. Bruce, having despatched Douglas, Sir Alexander Fraser, Sir William Wiseman, and Sir Andrew Gray, with a body of archers, to fetch a circuit above Lorn's ambush, boldly advanced up the pass. Lorn's men attacked, tumbling stones down the slope; but, finding themselves caught in the rear, they fled down hill to a bridge crossing the river at one end of the loch, and, having crossed, attempted to break down the bridge. Bruce was upon them before they could effect their purpose, and completely defeated them. Having rapidly overrun Lorn's country, he took Dunstaffnage, and received to his peace Alexander of Argyll, while John of Lorn, 'rebel as he was wont to be,' escaped by water. Bruce then received the homage of all the men of Argyll, and returned to Perth.

But these events must have been spread over a considerable time, and they may not have been continuous. The record of Bruce's Parliament at St Andrews on March 16, 1308–9, places it beyond doubt that Alexander of Argyll came to Bruce's peace; it states that Alexander himself and 'the barons of the whole of Argyll and Inchegall' were present as liegemen of Bruce. Again, on June 16, 1309, both Alexander and John of Lorn were present at Edward's council at Westminster as liegemen of the English king. Further, we have a letter of Lorn's, undated, but replying to a letter of Edward's dated March 11, in which he says that he had been on sick-bed for half a year; that Bruce 'had approached his territories with 10,000 or 15,000 men, it was said, both by land and sea,' while he 'had no more than 800 to oppose him,' and 'the barons of Argyll gave him no aid'; that a truce had been made, at the instance of Bruce; that 'he hears that Bruce, when he came, was boasting that he (Lorn) had come to his peace,' 'which God and he (Lorn) knows is not true'; that, on the contrary, 'he is, and will ever be, ready to serve him (Edward) to the utmost of his power'; that 'he has three castles to guard, and a loch twenty-four leagues long, on which he has vessels properly manned, but is not sure of his neighbours'; and that 'so soon as the King or his power arrives, he will be ready with lands, ships, and others to aid him,' either in person (if he be not sick), or by his son. Neglecting minor discrepancies, one may safely accept Mr Bain's reconciliation of the various accounts. Alexander came to Bruce's peace after the affair of Loch Awe; John was still holding out in March, but was driven from Dunstaffnage within the next two months; and Alexander thereupon retired, with John, to England. Alexander died in Ireland in the end of 1310. John lived to fight for Edward some seven or eight years more; but, as Mr Bain gently remarks, 'Barbour has strangely misrepresented his later career.'

Bruce was now master in the west as well as in the north. Beyond Forth, however, Perth, if ever captured, must soon have been recovered; and Dundee—and even Banff—remained in English hands, as well as the key-fortress of Stirling on the south bank of the dividing river. Still Bruce was master of the country, and he was free to turn his attention to the south.

Sir Edward Bruce, after an arduous struggle, had taken a firm grip of Galloway by the end of 1308. With Lindsay, Boyd, and Douglas he had attacked the Galwegians—'notwithstanding the tribute they received from them,' says the Lanercost chronicler, who also admits that they 'subdued almost all that land.' According to Barbour, Sir Edward met the English near Cree, routed them, slew some 1200, and pursued Umfraville and St John to Buittle Castle. St John then rode to England and brought up over 1500 men; on hearing which, Sir Edward instantly mounted, with 50 men, followed up the trail of the enemy in the morning mist, and, when the day cleared and he found himself within bowshot, charged with his usual reckless audacity. The English believed there must be more men with Sir Edward than they saw. At the third charge he routed them, slaying or taking many; St John, however, escaping. Sir Allan de Cathcart, Barbour affirms, 'told me this tale.' Sir Edward had all Galloway at the King's peace.

Fordun, again, relates that Sir Edward, on November 18, inflicted a crushing defeat on Donald of the Isles and the Galwegians on the river Dee (not Cree), taking Donald prisoner in his flight, and slaying 'a knight named Roland, with many of the nobles of Galloway.' Whatever the dates and the details, Sir Edward must have done some stern fighting. The Lanercost chronicler even records that it was said that the English king would have liked, if he could, to give Bruce peace on terms of aiding him against his earls and barons.