On the latter joining the insurgent camp in Braemar, he was at once despatched by the earl to Aberdeen, to raise in arms the descendants of 300 MacGregors, who had been forcibly conveyed there in 1624 by James Stewart, Earl of Murray, to fight in the feuds in which he became involved with the Grants, MacIntoshes, and others. In this mission Rob was pretty successful, for the popularity of his name, among his own clan and others made him an excellent recruiting officer at this crisis; and so little did he value the Whig Government and their proclamations that he walked openly about the streets of the Granite City, and on more than one occasion dined with Professor James Gregory, who was by descent a MacGregor, but had thus altered his name to elude the Act which proscribed it. He joined the Earl of Mar in time to be present with his clan at the great battle of Sheriffmuir, where the insurgents met the king's forces led by the Duke o' Argyle, who was then lieutenant-general, knight of the garter, and commander-in-chief of the troops in Scotland. It is no part of our plan to give any history of that indecisive battle, which was severe and bloody to both parties. Both armies wheeled upon their centres, and each routed the other's left wing, so that it is impossible to say with whom lay the victory. On that day, Rob Roy, who commanded a body of MacGregors and MacPhersons, was accused of unwillingness to engage. His enemies went further, and asserted that, not wishing to offend his patrons the powerful Duke of Argyle and Earl of Breadalbane, save for whom he would have been crushed long ago by the Duke of Montrose, he remained almost aloof from the action. Lack of interest in King James's cause, or lack of courage could not be laid to his charge; yet on this great day the conduct of Rob Roy was incomprehensible. Scott relates in his History, that when ordered to charge by one of Mar's _aides-de-camp_, he replied-- "If the earl cannot win the field without me _now_, he cannot win it with me." From this it may be supposed that he considered the decisive moment past, and wished to spare his men; but, it is said, that on hearing this answer, a brave man of the Clan Vurich, named Alaster MacPherson, cast his plaid on the ground, drew his claymore, and called to the MacPhersons-- "Advance--advance!--follow _me_!" "Halt, Alaster," said Rob, interposing; "were this a question about a drove of sheep you might know something; but as the matter concerns the leading of armed men, you must allow _me_ to judge." "Were the question about the foraying of a drove of Glen Eigas stots, the question with you, Rob, would not be who should be last, but who should be _first_," was the stinging retort of MacPherson.