ENRiksarkivet, the national archive in Stockholm, contains a sheath of documents relating to the heritage of Polish and Lithuanian rulers - Sigismund the Old, Bona Sforza, and Sigismund Augustus and his sisters - titled Summarium Testamentu The documents were most likely written during 1572-1574, with one ruler succeeding another, when the heir of the enormous private property of Sigismund Augustus was yet to be known. The lists enumerate the Goštautas’ domains that passed onto King Sigismund the Old, including Liubavas (Pol. Lubow). This new information is an addition to the published messages about the rearrangements at the royal manor of Liubavas that took place in 1544-1547 when the rule over the Great Duchy of Lithuania was taken over by the young Prince Sigismund Augustus. The Goštautas family ruled Lithuania back in the 15th century, because on 16 June 1471 in Geranainys, Kiev voivode Martynas Goštautas signed at the Dieveniškės church of St. Michael an allowance letter for the altar of St. Virgin Mary submitted by altarist Jonas, granting a tithe from Liubavas manor for the upkeep.As Dieveniškės had been granted to Vilnius voivode Jonas Goštautas, Martynas’ father, by the Grand Duke in 1433, the Goštautas family can be assumed to have ruled Liubavas since the first half of the 15th century. This would suggest that Liubavas is one of the oldest private manor sites in Lithuania that in the 16th century would turn into boroughs and towns, such as Daugėliškis, Žąsliai, Rokantiškės, as often as not. However, adverse circumstances had prevented Liubavas from evolving into a larger administrative unit and the manor had retained its private status until mid-20th century. That is why the topography of the locale might have preserved remnants of the ancient Lithuanian manor site, such as defensive fortifications and a folwark.