The Scottish jurist William Barclay invented the term ‘monarchomach’ in his treatise on kingship, De Regno et Regali Potestate (1600). He used it to describe a genre of seditious texts written in France and Scotland from the 1570s through to the 1590s, which form the spine of the material considered in this book. Broadly speaking, these works defended the notion that a contract existed between the people, their ruler and God. They argued that if the terms of that contract were broken, power would revert to the people who could, as a whole, legitimately depose, or even authorise the assassination of a monarch. ‘Monarchomach’ was interpreted to mean ‘king-killer’, and it continues to be used to describe the genre to this day.