Born in Poland in about 1185, he received a good education in Paris and Bologna, and became well known for his studies and works to reform women's monasteries in Poland. He went to Rome and witnessed St. Dominic perform a miracle, so he decided to become a Dominican Friar, receiving his habit from St. Dominic himself. He along with a companion went back to their home in Poland to establish the Dominican Order there.
Hyacinth about to take the statue (notice the burning monastery in the background?)
A popular miracle attributed to St. Hyacinth is the story of the attack on the monastery by the Mongols. St. Hyacinth heard about the attack after celebrating Mass, and went to the tabernacle to save the host in the ciborium (or the monstrance, it depends), when, while passing the statue of the Blessed Mother, heard a voice say, " Hyacinth, My son, why do you leave Me behind? Take Me with you." He went to pick the heavy alabaster statue up, and it was as light as a feather.
He was advised of his coming death on the eve of the Assumption. Although sick with a strong fever, he celebrated Mass. He was given last rites at the foot of the altar and died on the great feast of Our Lady, 1257.