The administration of the Norman kingdom of Sicily has long been held up to be the most advanced government in 12th-century Europe. However, until now there has been considerable confusion about how this bureaucracy actually functioned: whether it developed in the 12th century or retained the form given it by Roger II; whether it had regional variations; what the identity of different departments of government were; who did what within the structures of government; and what the relationship between the Greek, Arabic and Latin elements were within the adminstration. This work aims to sort out these problems. The author's study of chronicles and charters enables him to clear up many problems and mysteries in the administration of finance and justice and to identify such uncertainties as remain. The book is designed to form a basic reference point for future studies of Norman Sicily and of government in the high Middle Ages.