Returning to Bucharest, he maintained this function under successive reigns, including that of Alexandru IV Iliaș. In 1629, Leon Tomșa promoted him to "Logothete" of his privy council. Also that year, Năsturel published the first of his many Slavonic prefaces, for a Nomocanon edition printed at Kiev. According to historian George Potra, he was the official translator for Prince Radu Iliaș when, in early 1632, Bucharest was visited by Paul Strassburg, diplomat of the Swedish Empire. From 1625, Năsturel had been married to Maria Corbeanu, of the Corbi boyars. He was also brother-in-law of another "Logothete", Radu Staico Popescu. At age 35, his other sister, Elena, became Wallachia's Princess-consort. As a teenager (most likely in 1613), she had married "Aga" Matei, later styled "Matei Basarab", who controlled an army of "Seimeni" mercenaries in Bucharest. In late 1632, at age 53, Matei defeated Radu Iliaș and took the throne for himself. Elena played a direct part in Wallachia's administration shortly after this—namely, during the interval when Matei negotiated his confirmation by Wallachia's suzerain power, the Ottoman Empire. Udriște's father, Radu, served as the country's treasurer ("Vistier") during the same hiatus. After Matei secured his throne in 1633, Elena turned to cultural endeavors, one of the principal sponsors and promoters of early Romanian literature. Udriște, a "Logethete" of the court in 1632, partook directly in her experiment. He is for instance credited with having helped the princely couple set up three printing presses, at Câmpulung, Dealu Monastery, and Băile Govora. As "Logothete", he directed the Chancellery, which issued some 1,300 documents during his tenure, all of them surviving. His correspondence attests links with intellectuals of various faiths: the Orthodox Gavrilo Rajić, Macarios Zaim, Peter Mogila, and Meletios Sirigos; and the Catholic Rafael Levaković, with whom he discussed the Nicene Creed. He also had oratorical duels with Constantin Cantacuzino, with bishops Varlaam Moțoc and Ștefan I, as well as with his sister the Princess.