A necessary assumption in Charles's mind when he resolved to venture a second military expedition against the Covenanters was that an efficient and effective fighting force could be raised from his other kingdoms. Administratively and financially this would prove to be a challenge too great to be met, but within that there were political troubles. The processes set in motion gave rise to major crises in both England and Ireland. The explanation of much that happened is to be sought where most commentaries have looked, namely in the relevant domestic arenas. What is attempted here is rather an examination of particular aspects of the background to the British dimensions of those troubled years.

The Scottish troubles developed out of problems involved in the rule by one king over three kingdoms. In particular they focused on ecclesiastical policy, but the resentment at allegedly anglicising corruptions could be shared by many who felt unhappy about Scotland's relations with England. The contrasts were often drawn in black and white; the Covenant cause was the patriotic one for Scots. At the same time, their feeling for the Reformed communion and their knowledge that there were some in England and Ireland of similar mind naturally brought Scots complainers to consider the extent to which their own plight was a common one, with a common enemy in popery. Finally, as the king threatened force of arms against what was reckoned to be a stance on truth, it became expedient as well as desirable to cultivate sympathies outside Scotland.