Ever since the early beginnings of human civilization there has been the startling question of what constitutes and determines one's social relations. Is the character of society as a whole shaped by the social forces existent in it or is the social differentiation a product of a particular political or cultural system? While apparently even the most ancient societies exhibited a clear distinction between those who exercised power and those who did not it has been left to numerous philosophers to provide sufficient and satisfying answers to the questions of where this distinction originates from and how, if at all, it can be justified. Once the first claim to property had been made both the claim and the property had to be defended and justified and thus the foundations for society's political, legal and maybe even cultural institutions were laid. Logically, these were to a large extent shaped by the interests of those possessing property. It is on these assumptions that modern class theory is built. Although the idea of economic determinism, i.e. the belief that the entire life is dependent on one's economic situation, had been present long before it was Karl Marx who was the first to develop a comprehensive framework around this idea. This paper attempts to outline the important features of Marxian class theory and to introduce some of the developments which took place in its tradition.