The thesis examines the social basis of the property and contractual relations of social groups in German East Africa. Chapter 1 oonsiders property relations arising principally from the labour of the producer. Social groups characterised by a communal mode of production are subdivided into shifting and stable sub-forms. In the first form, production units comprise production communities and family work-teams. In contrast to Meillassoux's study of the Guro, property relations are realised atthe level of the work-team. Land tenure in the two sub-forms differs, reflecting distinct practices in agriculture and labour organisation. Chapter 2 examines property relations arising from the direct appropriation of surplus labour by non-producers. Tributary and feudal modes of production are distinguished. Forms of tribute are examined. The 'bundle of rights' concept and Honore's theory of ownership are criticised. Chapter 3 concerns the social dissolution of the two previous forms of property due to the growth of commodity relations. Forms of sale, lease and mortgage are examined. The notion of 'absolute title' is analysed and comparisons with English Law made. Chapter 4 is a theoretical study of forms of exchange and corresponding legal relations. Chapter 5 applies aspects of the theory to contracts in East Africa. Contracts were generally not enforced. The significant point in the emergence of a law of contract was in debt relations. Generally loans were made without interest. In this case there is no distinction between restitution and enforcement of a promise. Instances of charging of interest are found where trade was developed. The Islamic rule against usury was found on the coast, but numerous exceptions developed. The enforcement of interest necessarily implies the enforcement of a promise and hence the emergence of a law of contract.