The subject of this paper is the development of societas (partnership) throughout periods of Roman law history. This paper presents and pinpoints all aspects of this notorious type of consensual contracts. Introduction shows historical development of the societas institute as a contractual relationship. The main body of the paper contains analyses of individual elements of societas institute and its base characteristics, such as legal nature of the institute, its kinds, and its special law structure. The paper enables a perspective into the position of partners as co-contractees among each other, as well as their relationship towards third parties. The last chapter of the paper explains the impact of the Roman institute of private law – societas onto contemporary legal regulations, i.e. their impact onto law obligatory contract concerning partnerships, following its arrangements as put forward by Civil Obligations Act of Republic of Croatia. Analysing the regulations made by legislator of positive law of Republic of Croatia, which govern the issue in question here, it is obvious to recognize the impact of the Roman law tradition taken over for its superiority and rationality. Law tradition of governing and determining legal relationships, characteristic and peculiar among the partners in Roman private law, had certainly ensured universal and timeless law solutions when it comes to arranging partnership contracts.