Aberdeen 13 September 1644

After his victory at Tippermuir and the capture of Perth, the Marquis of Montrose received news that the Marquis of Argyll was marching from the west with a large Covenanter force. Anxious to keep up the momentum of his campaign, Montrose left Perth on 4 September 1644 and marched north-east along the Firth of Tay. The well-defended town of Dundee was summoned to surrender but refused, so Montrose continued towards Aberdeen. Although many of the Highland clansmen departed with their plunder after Tippermuir, Montrose was joined by the Earl of Airlie and other local gentry along the way.

Montrose appeared before Aberdeen on 12 September with a force of Irish and Highland infantry and a small troop of 50 horse. On 13 September, the town was summoned to surrender. During the negotiations, a soldier from the Covenanter garrison is said to have shot and killed a drummer boy accompanying the heralds, infuriating Montrose and his troops who swore vengeance on the Covenanters of Aberdeen.

Having refused the summons, the Covenanter garrison under the command of Lord Balfour of Burleigh marched out and deployed on a crest before the town with around 2,000 foot and 500 horse. Montrose divided his troops into three. The centre, armed only with dirks and claymores, were to charge the Covenanter infantry. Musketeers and two dozen horse on each wing were to hamper the Covenanter cavalry. Trusting to their superiority in cavalry, the Covenanters tried to outflank Montrose's forces and encircle them. The musketeers coolly let the Covenanter horse ride by, then turned about and opened fire. Cut off from their own infantry and with Montrose between them and the town, the cavalry fled the field. At the same time, MacColla and the Irishmen in the centre charged up the slope towards the Covenanter infantry, sending them fleeing back into Aberdeen. Montrose's forces poured in after them.

The town of Aberdeen was subjected to a three-day orgy of plunder, pillage and rape which Montrose was apparently powerless to prevent. On hearing that the Marquis of Argyll's pursuing army was at Brechin, Montrose read the King's proclamation against the Covenant and withdrew towards the Highlands.

While Alaisdair MacColla went to recruit in the west, the armies of Montrose and Argyll manoeuvred in the hills north-west of Aberdeen. On 27 October, Montrose occupied Fyvie Castle. For two days, the Royalists and Covenanters skirmished around the castle, but neither side could gain an advantage. After Argyll withdrew, Montrose marched back across the hills to Blair Atholl.