His grandfather Đorđe Vasiljević Vojnović (1760–1821) was a Russian military officer, he later returned to Boka Kotorska, and in 1800, in Ancona, he married Kasandra Angeli-Radovani from a Roman Catholic family.

Count Jovan Đ. Vojinović (1811–1837) died at the age of 26, he married Katarina Gojković whose mother was of the family of Serbian Orthodox Metropolitan Stevan Stratimirović.

As the people's deputy he fought against the Austrian politics that deliberately omitted the Bokan maritime affairs, which was the main occupation of his ancestors.

Konstantin and Đorđe were baptized in the Serbian Orthodox Savina monastery in Herceg Novi, however, their grandmother Kasandra later converted them into the Roman Catholic confession.

At the recommendation of his close friend and a colleague Josip Juraj Strossmayer, he was elected in 1874 as a professor of Austrian law at the University of Zagreb.