A fascinating Dominican saint today: from a biography at an OP (not Ocean Pacific) website:

In 1218, Bishop Kadlubec retired, and Hyacinth’s own uncle, Ivo Odrowaz, was selected as his successor. He immediately set out for Rome to confirm his appointment, and Hyacinth was among his companions. St. Dominic was at Rome at that time, and had just performed one of his most famous miracles, that of restoring life to a young boy who had been thrown from his horse. Because of Dominic’s saintly reputation, Bishop Odrowaz sought him out and asked him to send some of his friars to Poland. Dominic confessed that this was a dream of his, but he did not yet have enough friars to send any to Poland. Bishop Odrowaz, however, pressed Dominic all the more, and Dominic suggested that if the bishop were to leave a few of his companions in his care, he would give them the habit and train them in the life of the order, and after a short formation, he would send them to Poland. Bishop Odrowaz agreed, and gave to his care Hyacinth and three others (including Hyacinth’s brother, Bd. Ceslas).

The four of them received the habit from Dominic himself, who also trained them. Dominic thought them ready after only six months, and he used the powers given him by Pope Honorius III to let them profess their vows at that time and send them north. They were well received in Cracow, where they immediately established a Dominican house. They then went to work preaching throughout Pomerania, Prussia, Denmark, and Scandinavia. Everywhere he and his companions went, they converted many by their preaching and miracles. Many joined their order, and wherever they found a place that seemed promising, they established a Dominican house to continue the work in that area.

Hyacinth continued his preaching mission into Little Russia (Ukraine), Greece, Turkey, and Great Russia. In the two Russias, he was unsuccessful in his attempts to convert the reigning sovereign, but he did receive permission to preach publicly. He won many converts and established a convent in Kiev (which was the capital of both Little Russia and Great Russia at that time), but the Tartars besieged Kiev and took it. Hyacinth and the other friars were able to escape by walking on the water of the river to safety, and it was said that his footprints on the water could be seen for years.

At this point he returned to Cracow and visited the houses he had founded in northern Europe. He went to work among the Cumans in Hungary and Romania, but he felt that others had the efforts there well under control, so he moved on to south-western Russia, the territory of the Tartars who had destroyed his work in Kiev. He preached through much of Asia, and converted thousands, traveling as far as the old Kingdom of Thibet and Cathay (northwestern China).

Missionary zeal, defined.