ENIn 1941 a set of 15 paintings from former gallery of family’s portraits was brought to Lithuanian Art Museum (3 of them were smaller then others). None of them had an inscription that could help to identify a person it was depicting; therefore all of them were recorded as paintings of some unknown persons. Some time later, however, it was ascertained that in one of those three smaller pictures a painter has depicted a great hetman of Lithuania Michael Casimir Oginski (1728–1800). It was supposed that another picture from smaller ones could be a portrait of his wife Alexandra Czartoryski (1730–1798). At that point a search for any proof of the fact has been started. During this process it became clear that there are at least two portraits of this woman abroad in which she is depicted in his young age. Both of them previously were recorded as portraits of some unknown women. Publication overviews the history of this research and tells about the obstacles that prevented from the final statement that the picture stored in Lithuanian Art Museum is one of a widow of Podlachia province’s governor Michael Antony Sapieha, a wife of the great hetman of Lithuania Michael Casimir Oginski, an active figure in culture and politics at the Age of Enlightenment, a patron that generously contributed to the prosperity and enlightenment of Siedlec area (Poland).A portrait of Alexandra Czartoryski with its name on it was exhibited for the first time in Vilnius Picture Gallery during the exhibition called “Creators of Lithuanian State” arranged in 2006. It was also published in the exhibition’s catalogue. At the moment the art of work together with other portraits of this family can be seen in the permanent exposition of Vilnius Picture Gallery. It is believed that the identification of the portrait belonging the collection of Lithuanian Art Museum will help to identify some more images of Alexandra Czartoryski that at the moment are similarly stored in collections of Lithuanian different museums under the record “the portrait of some unknown woman”.