Ostroh (;, ) is a historic city located in Rivne Oblast (province) of western Ukraine, located on the Horyn River. Ostroh is the administrative center of the Ostroh Raion (district) and is itself designated as a special administrative subordination within the oblast. The current estimated population is 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 pri… (More on Ostroh)