Social class schemes, contemporary as well as historical, always involve something of a mystery. While this book does not claim to have solved that mystery completely, it does shed significant light on it. For the sake of comparability, it is advisable not to develop new class schemes but to use old ones. Yet presenting a new class scheme - HISCLASS - is exactly what this book does. Unlike existing historical schemes, HISCLASS is international, created for the purpose of making comparisons across different periods, countries and languages. Furthermore, it is linked to an international standard classification scheme for occupations - HISCO. The chapters in the book show how historical occupational titles classified in HISCO can form the building blocks of a social class scheme for past populations. The dimensions underlying classes are discussed. How, for instance, can manual work be distinguished from non-manual work? Skilled from non-skilled? And what did ‘supervision' really mean? A rich source of detailed occupational information is used to measure those dimensions. The result is an instrument that can be used to systematically compare social class positions, distilled from a dazzling variety of occupational titles, around the world and over a range of periods.