Catherine I of Russia
According to Serbian poet and diplomat Jovan Dučić, descendant of Sava's either half-brother or first cousin Duka (whence the eponymic family name Dučić), "Sava Vladislavich occupied a distinguished position among Russian diplomats in the eighteenth century. During two and a half decades, he took part in all important events of the Russian empire as a legate of the Czar (Peter the Great) and Czarina (Catherine I of Russia)."