In the introduction it is defined the object of the study − the genealogy of the German noble family Naso and Polish noble family Nasuta. The aim of the study is to identify the genealogical origin of these aristocratic genera. In the main part the probable origin of these genera from the Hungarian nobility of Russian origin is shown for the first time. It is determined that the German genus (Latin Naso) with a high degree of probability came from Hungarian noblemen named Orro(u)s, whose Latin nicknames were Nasutus and Nasus and who moved in the first half of the 14th century to Prague. It is determined that the Lithuanian-Polish genus (Latin Nasuta) with a high degree of probability came from Hungarian noblemen named Orro(u)s/Rusas, whose Latin nicknames were Nasutus and Nusata and who retired to the service of Prince Mazowiecki in the early 1350s, and then transferred to the service of the Grand Duke Vitovt (until the 1370s). A linguistic evaluation of the name Nasuta is given. It is shown that its meaning coincided with the meaning of the corresponding Hungarian family nickname. The initial genealogy (14th–15th centuries) of these genera is constructed; and it is shown that direct descendants of these genera live in Belarus and Poland now, and distant relatives live in Russia (in the Nizhny Novgorod and Arkhangelsk regions). In the paper it is given an idea of the reasons of the mobility of the noblemen of medieval Europe. In the conclusion it is pointed that the obtained results should be considered as initial stage of further research with the aim of merging the restored initial genealogies of these genera and modern people of these surnames into a single whole.