Montrose's scheme implied clan warfare, the use of exiled Macdonalds, who were Catholics, against the Campbells.

The obvious objections were very strong; but "needs must when the devil drives": the Hanoverian kings employed foreign soldiers against their subjects in 1715 and 1745; but the Macdonalds were subjects of King Charles.
Hamilton's brother, Lanark, escaped, and now frankly joined the Covenanters.

Montrose was promoted to a Marquisate, and received the Royal Commission as Lieutenant-General (February 1644), which alienated old Huntly, chief of the Gordons, who now and again divided and paralysed that gallant clan.

Montrose rode north, where, in February 1644, old Leslie, with twenty regiments of foot, three thousand horse, and many guns, was besieging Newcastle.

With him was the prototype of Scott's Dugald Dalgetty, Sir James Turner, who records examples of Leslie's senile incompetency.