He was born into nobility in 1195. After completing his doctorate in law and divinity in 1220, Hyacinth traveled to Rome with his uncle (who was a bishop). There he met St. Dominic.
Hyacinth decided to join Dominic's Order of Preachers and became on if its first members. Dominic sent him to Poland to establish a Dominican community there. Eventually, Hyacinth's missionary work took him into Scandinavia, the Baltic countries and Russia.
He died in Krakow, Poland, on August 15, 2157, the feast of the Assumption of Mary.
Tradition states that when the Mongols attacked the city of Kiev in Ukraine, Hyacinth and his fellow friars prepared to evacuate. But before they left, Hyacinth rushed into the chapel to save the ciborium containing the Blessed Sacrament. As he prepared to leave the chapel, he heard the Blessed Mother asking him to take her too.
That is why St. Hyacinth is often pictured holding a monstrance and a statue of Mary.
- Little White Book, Diocese of Saginaw