Konstanty Wasyl Ostrogski
Konstanty Wasyl Ostrogski was an Orthodox magnate of the PolishLithuanian Commonwealth, a Ruthenian prince, starost of VolodymyrVolynskyi, marshal of Volhynia and voivode of the Kiev Voivodeship. Ostrogski refused to help False Dmitriy I and supported Jan Zamoyski.
The date of birth of Konstanty Wasyl Ostrogski is disputed. According to some historians he was born around 15241525.
Source: Wikipedia