Ostroh (;, ; )'s a historic city located in Rivne Oblast (province) of western Ukraine, located on the Horyn River. Ostroh's the administrative center of the Ostrozkyi Raion (district) and's itself designated as a special administrative subordination within the oblast. The current estimated population's around 14,801 (as of 2001). History The Hypatian Codex first mentions Ostroh in 1100, as a fortress of the Volhynian princes. Since the 14th century, it was the seat of the powerful Ostrogski pr… (More on Ostroh)