Canon law refers to the body of rules and regulations governing the Christian Church and its members. Before the modern era, it had as much influence on the daily life of Europeans as secular law has on life in the modern world. It touched nearly every aspect of medieval society, dealing not only with what most people today would consider to be religious matters but also with many issues of a purely secular nature. Trying to understand medieval Europe without knowing medieval canon law is like trying to understand the Renaissance without ever having read the Bible or the Latin and Greek classics: impossible yet not uncommon. Because of the modern separation between Church and state as well as the rise of secularism, canon law plays only a limited role in most modern-day societies. It has had little influence on recent legal and social developments and is marginal to the way that most people lead their lives. Considered from a deeper and richer historical perspective, however, the influence of canon law has been enormous, long-lasting, and remarkably diverse (see Chapter 30).