Reading his Way to Royalism? Sir Thomas Myddelton, Side-Changing and Loyalty in England and Wales, 1639–66

Abstract Civil War allegiance has long been a preoccupation of early modern British historians. They have weighed geographical, religious, political, and pragmatic reasons for British people to choose sides in 1642. A study of the changes of allegiance in the years that followed is just as important. Side-changing reveals the fractures and difficulties that war, regime change, and an uneasy peace created. Most scholarship has examined figures whose ideas and beliefs remained consistent as the world around them changed. This article argues that others changed their minds (and their side) because their ideas fundamentally shifted, through an engagement with oppositional literature, a royalist social environment, and relationships built with royalist agents. Through a case study of the parliamentarian Major-General Sir Thomas Myddelton it examines this process of change. The article takes the study of allegiance into the Interregnum and beyond to the Restoration, tracing the impact of Myddelton's reading, experiences, and actions upon his declared loyalty. To do this, the article proposes a methodology that cuts across historical approaches, using evidence from financial accounts, libraries, and legal cases alongside surviving correspondence and printed pamphlets to build a composite image of a changing mind.