The basic question of hereditary law is who will be the successor or who will be entitled successor (beneficiary) after the death of the deceased. The answer to this question, starting from the Roman law until today, is solved the way that the deceased determines the successor by a will, either during his lifetime, or the person becomes a successor pursuant to the law. Accordingly, there are: testamentary and legitimate inheritance. The subject of this paper is an analysis of the development of testamentary inheritance from the historical period of Roman law up to the contemporary Croatian law, as we know it today. The testament is one of the fundations of succession, known in the Roman state since the earliest times. It was created alongside the development of private property. During the course of historical development, the testament has changed its forms and functions. However, some notions such as the subject and the content of testamentary disposition, and the appointement of successors, substitutions and the like have been retained until today, with the same or similar contetnt. Futhermore, the very division of the form of will in Roman law remained almost identical to the present one. Thus, it is evident that the Roman law has had an important impact, both on the development of testamentary inheritance, as will as on the contemporary inheritance law, in general.