This rigorous work deals with the testamentary succession which is complemented with a new institute within the law of succession regulation - fideicommissum. The content of the work is divided into five main chapters whereas it is proceeded from general interpretation of law of succession taking into account history because above all the law of succession it one of the branches of the Civil Law which was a subject of great changes within the re-enactment of the Civil Law and it is getting back to the institutes which the existing legal regulation did not know. The introduction addresses explanation of basic terminology within the matter of law of succession; it elaborates fundamentals, principles and functions of the law of succession and ...