Hyacinth (Jacek Odrowąż in Polish) was a Silesian-Polish nobleman, educated at Kraków, Prague, and Bologna, and was canon of Kraków cathedral when his uncle Bishop Iwo Odrowąż took him on a journey to Rome in 1217. There they met Dominic of Caleruega, just two years before Dominic's death. Hyacinth and his cousin Bl. Ceslaus received the Dominican habit from Dominic himself and were sent back to plant the order in northern Europe.
Returning home he founded the first Dominican priories at Friesach (1219), Kraków (1222), Prague (1226), Gdańsk (1227), and Wrocław, then carried the order to Kievan Rus' (where he founded a priory in Kiev itself), to Prussia, and possibly to the Black Sea region of Crimea — though some claims about the eastern extent of his journeys are difficult to verify. He is the proto-apostle of the Dominicans in eastern and central Europe.
The most famous episode of his life: when the Mongols overran Kiev in 1240, Hyacinth — at Mass in the Dominican church — heard the Virgin's voice telling him not to abandon her. He carried out the ciborium with the Blessed Sacrament and a heavy stone statue of the Virgin Mary on his shoulders, escaping across the Dnieper river; tradition holds that the statue became weightless on his back. He died at Kraków on the feast of the Assumption, 1257, and was canonized in 1594 — the second formally canonized Polish saint after Stanislaus of Szczepanów.