[1] During the Serbian Revolution (1804–1813) he was part of the Serbian rebel government,[2] and served as the Minister of Foreign Affairs as part of the Cabinet of Karađorđe Petrović (1811–12).
[3] He taught German at Belgrade's Grande école (est.
After Trieste, he went to Wallachia (today's Romania) where he engaged in trade.
Radonjić was the first Foreign Minister in the modern history of Serbian statehood.
He was appointed to that position when the previously appointed Milenko Stojković (from January 11, 1811) refused to enter the Governing State Council and accept the duty of minister.