Jean Calvin, in his Institutes of the Christian religion, wrote that ‘there is a twofold government of man; one aspect is spiritual…the second is political…. There are in man, so to speak, two worlds, over which different kings and different laws have authority’. He emphasised this further by stating that ‘we must keep in mind that distinction which we previously laid down so that we do not (as commonly happens) unwisely mingle these two, which have a completely different nature’. The idea of the separation of spiritual and temporal jurisdictions was, of course, no post-Reformation innovation but had been a theme over centuries of conflict between popes and secular princes throughout Europe. With the fragmentation of western Christendom in the sixteenth century, the issue came to prominence within individual states, not least Scotland. As early as 1559, during the civil war which led to the Reformation, a letter to the regent, Mary of Guise, from ‘the professouris of Christis ewangell’ mentioned two ‘kingdomes’. It asserted that there was ‘ane kingdome temporall’ and ‘Christis kingdome’, the Kirk, and that the former ought to be ruled by ‘mortell men’ and the latter by Christ alone. The regent was described as ‘ane servand and na quein havand na preheminence nor authoritie above the kyrk’.