Coloman was king of Hungary from 1095, Croatia from 1102, and Dalmatia from 1106. His father was King Géza I and his mother was Queen Sophia.

Coloman was originally destined for a career in the church, although he rose to the rank of high priest. He became the bishop of Eger and Nagyvárad. Saint Ladislaus's designated successor was actually Prince Álmos, but after the king's death Coloman took over the throne. The prince fought for years to claim the throne. After a while, Coloman satisfied this and blinded him. His successors tried to give him a bad name in the country, but his politics were considered very enlightened in the Middle Ages.

Coloman relaxed the laws of his predecessor, Ladislaus. Among other things, he abolished forced confession, accepted priestly celibacy and renounced the right of investiture. Furthermore, he made the church's sanctification of marriage mandatory and set up the bishopric of Niitra. At the Council of Esztergom, he ordered that the canons speak Latin to each other.

He died in 1116 and his son, Stephen II came to power. However, Stephen was left without a successor, so the crown passed to the Álmos branch.

During the reign of Coloman, the money corruption began, which greatly reduced the weight and fineness of the 12th century money with the help of the annual coin renewal. The name of the issuing monarch was not even displayed on the denarii, their medal images were mostly geometric figures, crosses, and crescents.