The Ostrogski family was most likely of Rurikid stock and descended from Sviatopolk II of Kiev. Some scholars however claim that their descent is from the Galicia-Volhynia line of the Rurikid dynasty. Vasilko Romanovich (c.1256-1282), Prince of Slonim, may have been the grandfather of Prince Daniel Ostrogski.[4] The probable progenitor of this family was Prince Danylo Dmytrovych (or Danylo Wasilijewicz), who received Ostroh from Liubartas, King of Galicia-Volhynia and son of Grand Duke of LithuaniaGediminas. His son, Prince Feodor Danilovich Ostrogski, was a supporter of King Jagiello, who in 1386 confirmed him in possession of the Ostroh Castle and appointed governor of Volhynia in 1387.[5] In addition to Ostrog Feodor Danilovich Ostrogski became owner of Korets, Zaslav (Izyaslav, in present Khmelnytskyi Oblast, Ukraine), and other towns. In some chronicles Feodor is called Dux Fethko de Ostrog.[6]
Their dominions in Volynia, Galicia, and Podolia included 24 towns, 10 townlets, and more than 100 villages.
The last male member of the family was Janusz Ostrogski (d. 1620); the last female was Anna Alojza Ostrogska (1600–54), married to Grand Hetman Jan Karol Chodkiewicz. When a junior line of the family (princes Zasławski or Zasławski-Ostrogowski) which inherited the Ostrogoski fortune became extinct in 1682 (with the death of Aleksander Janusz Zasławski), their huge possessions passed to the Lubomirski family (due to their marriage with Aleksander sister, Teofilia Ludwika Zasławska) and other families of Polish szlachta. A complicated litigation concerning the Ostrogski inheritance continued until the Russian Empire annexed Poland during the Partitions.
