From 1540 onwards, successive English rulers appear to have exercised a choice between two strategies. During the ‘Catholic’ phases of the next thirty years, the final part of Henry's reign and the whole of his daughter Queen Mary's, the crown made use of parliament at its convenience, but it also enjoyed considerable success in levying non-parliamentary taxes. It was only in the period's ‘Protestant’ phases, under the two Edwardian dukes and Queen Elizabeth, that there emerged a bias towards law-bound government. So far as we know, this shift owed almost nothing to Protestantism among common lawyers; if the profession as a whole had a religious preference, it lay in a conservative direction. The likely explanation of the new respect for law is that it reflected the Protestants' perception of the exigencies of their position: the Catholic governments fought wars that gave them excuses for cutting legal corners; the Protestants too fought wars in France and Scotland, but they appear to have judged themselves to be too insecure to take their opportunities of using ‘regal’ power.
Both types of ruler had to face the problems that were caused by Henry's extravagant quest for martial glory. In October 1542, Henry invaded Scotland, apparently as a preliminary to a more cherished military project: the invasion of France he undertook in 1544. But in December 1542 the unexpected death of the Scots king created a dangerous vacuum in Scottish politics necessitating further intervention.