How a judge holds his office, that is, the type of tenure a judge enjoys, has long been touted as one of the key pillars of judicial independence. Judicial tenure ‘during good behavior’ (quamdiu se bene gesserint) – as opposed to the more precarious judicial tenure ‘at will’ – has traditionally been viewed as a seventeenth-century legal innovation created to shield British high court judges from arbitrary removal by the king. And drawing upon this seventeenth-century English tradition, all United States federal judges continue to fill their offices ‘during good behavior’.

However, judicial tenure ‘during good behavior’ is of far more ancient date. Using a range of primary sources, this article will be the first to trace the rise and development of judicial tenure ‘during good behavior’ from its earliest recorded instance in the thirteenth century through the fifteenth century.

The evidence illuminates that judicial tenure ‘during good behavior’ was widely used by medieval British monarchs to bestow a more secure form of judicial office than that granted by tenure ‘at will’. Furthermore, primary sources offer some insight into what the king (and perhaps medieval society) considered bad behavior, and thus grounds for judicial removal. Finally, by examining the development of judicial tenure ‘during good behavior’ over time, this article dispels the myth that judicial tenure ‘during good behavior’ began in the seventeenth century. Rather than creating a new form of judicial tenure, seventeenth-century legal reformers were instead reinterpreting well-worn medieval principles to suit their own aims.