Christianity has had a problematic relationship with warfare throughout its history, with the middle ages being no exception. While warfare came to be accepted as a necessary activity for laymen, clerics were largely excluded from military activity. Those who participated in war risked falling foul of a number of accepted canons of the church as well as the opinions of their peers. However, many continued to involve themselves in war - including active participation on battlefields. This book, focusing on a number of individual English clerics between 1000 and 1250, seeks to untangle the cultural debate surrounding this military behaviour. It sets its examination into a broader context, including the clerical reform movement of the eleventh and twelfth centuries, the development of a more comprehensive canon law, and the popularization of chivalric ideology. Rather than portraying these clerics as anachronistic outliers or mere criminals, this study looks at how contemporaries understood their behaviour, arguing that there was a wide range of views - which often included praise for clerics who fought in licit causes. The picture which emerges is that clerical violence, despite its prescriptive condemnation, was often judged by how much it advanced the interests of the observer.