The article focuses on the feudal conditions – vassals and fiefs – in the territory of Ribnica between 1418 and 1456, i.e., at a time when the former Ortenburg fiefs were in the hands of the Counts (later Princes) of Cilli. Between the mid-thirteenth and early fourteenth century, the Counts of Ortenburg received in fief from the Aquileian Patriarch a vast complex of landed estates, including Ribnica, in Lower and Inner Carniola. Following their extinction (1418), this estate passed into the hands of the Counts of Cilli. After the death of Herman II of Cilli (1435), the helm of the family was taken over by his son Frederick II, who renewed his confirmation or, rather, feoffment of the Cilli fiefs. This is how the fief book was compiled in 1436, now the oldest preserved inventory of the Cilli fiefs, in two not entirely identical copies; one is kept by the Archives of the Republic of Slovenia and the other by the Styrian Provincial Archives in Graz. In a similar vein, two new fief books were compiled after the death of Count Frederick II of Cilli (1454), one for the County of Ortenburg and one for the County of Cilli. Both are kept by the Archives of the Republic of Slovenia in Ljubljana. The murder of Ulrich II of Cilli (1456) left the family without its last male representative and after a short war, their property was taken over by the Habsburgs.