In 1995, the parish of the Holy Trinity Cathedral in Opole had its 700th anniversary of existing, but the begining of the church had been much earlier. In 1024, the bishop of Wrocław passed on relics of the Holy Cross, which he got from St. Emeryk as a gift, to the new church in Opole. Then, Opole changed its arms: a half of the Cross was added to the eagle of the Piasts. At the beginnings of XIIIth century, a chapter was appointed and the Holy Cross church bacame a collegiate church. In the middle of XIIIth century the parish and surrounding villages had already about two thousand believers. In 1295, thanks to generosity of priest Boleslaw I, there was built a basilica with tower in late-roman style, which bacame a genuine pride of the city. The collegiate church was consecrated on 16th of November 1295.