Kostiantyn Ostrozky

Kostiantyn Ostrozky (1526–1608) – Prince and Magnate in the Grand Duchy of Lithuania (on lands that once belonged to Kyivan Rus)

• Actions:
  • Amassed immense wealth and land in the Grand Duchy of Lithuania—his annual profits alone could have covered the entire budget of the future Polish-Lithuanian Commonwealth.
  • Fought in numerous wars to defend the Commonwealth.
  • Supported the Orthodox cause and the development of Ukrainian culture, primarily through donations to the Kyivan Cave Monastery and other churches.
  • Held great influence in the Polish-Lithuanian territories, regarded as the “unofficial prince of Rus,” continuing the legacy of Volodymyr the Great and Yaroslav the Wise.
• Significance:
  • Preserved the traditions of Kyivan Rus and defended Orthodoxy by organizing the Second Council of Brest (6_Religious Interlude), while also fostering intellectual life.
  • Seen by contemporaries as the successor to the legacies of Volodymyr the Great and Yaroslav the Wise.
• Successor and Legacy:
  • His family expanded their dominance in Ukraine; his great-grandson Janusz would later provoke the Kosiński Uprising.

This is part of the #Significantpersons series.