The present diploma thesis is dealing with the history of origins of substitution. The legal institution describes the contractual act on behalf of another person. To understand such a complex legal concept like agency, you have to examine the historical development. In Roman law, in which the substitution is rooted in, there were no such things like direct entitlement and obligation with effect on third party as in the present way, considering the roman principle alteri stipulari nemo potest, which opposed something like this. This principle was forming for all era of legal history in the historical development of direct agency. Not until natural law there were a disentanglement from the roman principle and a recognition of direct entitlement and obligation with effect on third party noted. In the ABGB 1811 the direct agency was codified in the “Bevollmächtigungsvertrag”, which didn`t change in the wording till this day.