"Sinaia Monastery
The monks possess a library that is a repository for valuable jewels belonging to the Cantacuzino family, as well as the earliest Romanian translation of the Bible, dated 1668."

https://en.wikipedia.org/wiki/Cantacuzino_family

The Cantacuzino or Cantacuzène family is a Romanian aristocratic family that gave several Princes of Wallachia and Moldavia, descending from a branch of the Byzantine Kantakouzenos family, specifically from the Byzantine Emperor John VI Kantakouzenos (reigned 1347–1354). After the Russo-Ottoman War of 1710–11 a lateral branch of the family settled in Russia, receiving the princely (Knyaz, as opposed to Velikij Knyaz) status. In 1944 Prince Ștefan Cantacuzino settled in Sweden, where his descendants form part of the unintroduced nobility of the country.
As a consequence of the Russian Revolution and the Soviet occupation of Romania after World War II, (between 1944 and 1947) the last two branches now mostly live in Western Europe and North America."