Battle of Aberdeen (1644)

• Royalist (James Graham, Lord Montrose)
  • Irish Brigade (Alasdair Mac Colla)
    • Thomas Laghtnan's Regiment
    • Manus O'Cahan's Regiment
    • James MacDonell's Regiment
  • Clan MacDonald of Keppoch
  • Sir Nathaniel Gordon's Horse
  • Sir Thomas Ogilvie's Horse
• Covenanter (Lord Balfour of Burleigh)
  • Lord Balfour of Burleigh's Regiment
  • Lord Forbes' Regiment
  • Aberdeen Militia (Maj. Arthur Forbes)
  • Aberdeenshire Fencibles
  • Cavalry units:
    • Sir William Forbes of Craigevar
    • Capt. Alexander Keith
    • Lord Lewis Gordon
    • 'Fencible' cavalry (Lord Fraser, Lord Crichton)

Montrose drew up an extended line of men. His left wing, under the professional soldier Colonel James Hay, included Gordon's cavalry and a small unit of Irish musketeers led by Captain Mortimer of O'Cahan's regiment. The right wing, commanded by Sir William Rollo, included Ogilvie's troopers and a number of Highland infantry; the centre was made up of the Irish under Mac Colla.[4] Burleigh placed the majority of his cavalry, under Crichton and Fraser, on his left flank opposite Rollo, where the gradient to the ridge was shallowest and his defensive position weakest, with his 'regular' cavalry on his right wing. The infantry was in the centre, with his Fife regiment, the strongest, towards the left of the position.[4] A number of Burleigh's musketeers occupied defensive positions in the buildings of the Justice Mills, on his right flank towards the west side of the battlefield.

The battle began with a cannonade from the Covenanters' field guns. The Royalist troopers on the left wing under Gordon attempted to drive some government musketeers out of the Justice Mills buildings, but were attacked by Alexander Keith's cavalry, who in turn were repulsed by a volley from Mortimer's musketeers.[4] Craigevar's cavalry troop then advanced downhill towards the Royalist positions of O'Cahan's regiment. O'Cahan's men simply parted to let the cavalry through, firing at the troopers' backs, and in the confusion the government troopers were then charged and routed by Gordon's horse. Craigevar and his second in command Forbes of Boyndlie were taken prisoner.

On the Royalist right wing, Sir William Rollo and MacDonnell's foot defended against several inconclusive attacks by Fraser and Crighton's fencible cavalry. Montrose ordered the remaining uncommitted Irish regiment, Laghtnan's, to advance up the steep slope towards the Government centre. There was an intense and probably prolonged firefight at the top of the ridge in the vicinity of the Crabstane of Aberdeen. The Aberdeen Militia gave way before a final "Highland charge" and fled into the town, pursued by Laghtnan's men, beginning a general retreat of the government forces. One unit, the Fife regiment, held formation and attempted to outflank the Royalists to the east with the intention of escaping southwards, but Montrose ordered MacDonnell's regiment to engage them. They were scattered with great loss of life, forming the majority of the 520 or so government casualties.[4] Royalist casualties are unknown, but thought to be light. The battle had lasted approximately two hours.[7]

The Royalist troops pursued fleeing troops from the battle into the town, and cut down and killed any men they found within it, according to the chronicler John Spalding, who was present.[6] The violence went on for several days. Goods were looted, women raped, and at least 118 (according to Spalding) and perhaps as many as 160 (according to Alexander Jaffray, who was also at the battle)[8] people were killed, including three members of the town council and a large number of tradesmen and ordinary residents.[6] Spalding recorded that the townspeople eventually took to wearing a twist of oats in their bonnets, the Royalists' badge, in an attempt to deflect the attentions of the marauding troops. "Ilk ane had in his cap or bonnet a rip of oats, whilk was his sign, our town's people began to wear the like in their bonnets, and to knit them to the knocks of our yetts, but it was little safeguard to us, albeit we used the same for a protection".[9] The episode did severe damage to the Royalist cause, particularly as Aberdeen had been in general sympathetic to the Royalists, and eliminated Montrose's chances of recruiting in the area. Despite the Royalist victory, this was probably the most significant outcome of the battle overall.