Battle of Alford

‘After some marching and counter-marching, the armies again found themselves in the neighbourhood of each other, near to the village of Alford. 

Montrose occupied a strong position on a hill, and it was said that the cautious Baillie would have avoided the encounter, had it not been that, having crossed the river Don, in the belief that Montrose was in full retreat, he only discovered his purpose of giving battle when it was too late to decline it. The number of infantry was about two thousand in each army. But Baillie had more than double his opponent's number of cavalry. Montrose's, indeed, were gentlemen, and therefore in the day of battle were more to be relied on than mere hirelings. The Gordons dispersed the Covenanting horse on the first shock; and the musketeers, throwing down their muskets and mingling in the tumult with their swords drawn, prevented the cavalry from rallying. But as Lord Gordon threw himself, for the second time, into the heat of the fight, he fell from his horse, mortally wounded by a shot from one of the fugitives. This accident, which gave the greatest distress to Montrose, suspended the exertions of the cavalry, who, chiefly friends, kinsmen, and vassals of the deceased, flocked around him to lament the general loss. But the veterans of Montrose, charging in columns of six and ten men deep, along a line of three men only, broke that of the Covenanters on various points, and utterly destroyed the remnant of Baillie's army, though they defended themselves bravely.’

The Battle of Alford took place on July 2, 1645, with James Graham and George Gordon leading a Royalist victory over Covenanting forces under General William Baillie.  The text above is found in Sir Walter Scott’s “Tales of a Grandfather”.

Battle of Aberdeen

'...It was owing to such causes, the slackness of the Lowland loyalists and the temporary desertion of his Highland followers, that Montrose found himself, even after the decisive victory of Tippermuir, in no condition to face the second army with which Argyle advanced upon him from the westward. In this emergency, supplying by velocity the want of strength, he moved suddenly from Perth to Dundee, and being refused admission into that town, fell northward upon Aberdeen, where he expected to be joined by the Gordons and other loyalists. But the zeal of these gentlemen was, for the time, effectually bridled by a large body of Covenanters, commanded by the Lord Burleigh, and supposed to amount to three thousand men. These Montrose boldly attacked with half their number. The battle was fought under the walls Of the city, and the resolute valour of Montrose's followers was again successful against every disadvantage...'

The text above is from Walter Scott's "A Legend of Montrose", and in a broad stroke treats the Battle of Aberdeen, which occurred on September 13, 1644.  In this battle, James Graham, 1st Marquis of Montrose, fighting as a royalist for Charles I of England, defeated Covenanter forces under John Balfour, Lord Burleigh.  The battle was part of the Wars of Three Kingdoms, which ran between 1644 - 1651.

Montrose

...' There is but One,' said Allan M'Aulay ; ' and here,' he said, laying his hand upon the shoulder of Anderson, who stood behind Lord Menteith, ' here he stands !'

The general surprise of the meeting was expressed by an impatient murmur; when Anderson, throwing back the cloak in which his face was muffled, and stepping forward, spoke thus :—' I did not long intend to be a silent spectator of this interesting scene, although my hasty friend has obliged me to disclose myself somewhat sooner than was my intention. Whether I deserve the honour reposed in me by this parchment will best appear from what I shall be able to do for the King's service. It is a commission, under the great seal, to James Graham, Earl of Montrose, to command those forces which are to be assembled for the service of his Majesty in this kingdom.'...
 
Walter Scott published "A Legend of Montrose" in 1819.  His named subject, James Graham, 1st Marquis of Montrose, was executed at Mercat Cross in Edinburgh on May 21, 1650.  The Wars of Montrose which transpired between 1639 and 1645 form a backdrop for the novel.
 
As a young man, Montrose became a Covenanter, signing the National Covenant in February 1638.  At least in part what instigated Montrose to join this cause was against the imposition of Laud's prayer book on the Scottish Kirk. 
 
Montrose is best known as a military man, and he gained his first experience leading Covenanter's troops in the First Bishop's War (1639).  After signing the Pacification of Berwick, Montrose ran afoul of Archibald Campbell, who was outwardly supportive of the Covenanters, but Montrose's suspected he had a contrary agenda.  Montrose's opposition to Campbell contributed to an invasion of England under the Second Bishop's War (1640).
 
Montrose corresponded with Charles I after the Bishop's War ended, later opposing the Solemn League and Covenant, which allied Scotland with English Parliamentarians against Charles.  He became a staunch Royalist, which is how Scott portrays him in the novel.