Testament in Roman Law with the Review of the Croatian Contemporary Law The freedom of testamentary succession was one of the fundamental elements of Roman private law and as such was also incorporated into contemporary continental European legal systems. Since the testament (will) is one of the most important institutions governing an individual’s property relationships, its relevance under private law has remained unchanged from its beginnings within the framework of Roman law to the present day. Through Roman history, the will has undergone various stages of development, changing its form and function. The aim of this work was to illustrate the evolution of will through different periods of development of Roman law and to see the extent to which this development has influenced the concept of will in contemporary law. A comparison with modern Croatian law shows how Roman law, in particular Justinian’s legislation, has had a major impact on the development of testamentary succession in modern law. For example, the types of wills formulated in Justinian’s codification have remained essentially unchanged to date. There are some minor differences in the form and content of wills under Roman law that depend on changes in social circumstances, to which the will has adapted during Roman legal history. Moreover, in modern law, there is also a certain degree of rigour in the drawing up of a will, in order to establish unequivocally that the content of the will is consistent with the testator’s last will, but also to avoid disputes between testamentary and legal heirs after the death of the testator and the heir to be really the closest person in testator’s opinion.