Career
Ostrogski refused to help False Dmitriy I and supported January Zamoyski. The date of birth of Konstanty Wasyl Ostrogski is disputed. According to some historians he was born around 1524/1525.
He was born probably in TuróWest
In the 1570s he waged a war against another magnate, Stanisław Tarnowski, about disputed possession of estates in the area of Tarnów, in Lesser Poland. Prince Ostrogski was of Eastern Orthodox faith and he was active in supporting the Orthodox Church (see Union of Brest).
He was also a promoter of Eastern Christian culture in the Polish–Lithuanian Commonwealth. Around 1576 he established the Ostroh Academy, a regarded humanist educational and scholarship institution, with the instruction in Greek, Latin and Old Church Slavonic languages.
In 1581 the Academy produced and published the Ostrog Bible, the first complete printed edition of the Bible in Old Church Slavonic.
Ostrogski"s huge latifundium, or landed estate in the eastern Polish–Lithuanian Commonwealth, consisted of 100 towns and 1300 villages. lieutenant was Ostrogski who built Starokostiantyniv Castle.