From its founding as a bishopric in until , it was under the Archbishopric of Gniezno in Greater Poland. From to it was subjected directly to the Apostolic See. Between and it was officially known as Arch Diocese of Breslau. Christianity was first introduced into Silesia by missionaries from Moravia and Bohemia.
After the conversion of Duke Mieszko I of Poland and the conquest of Silesia, the work of bringing the people to the new faith went on more rapidly. Up to about the year Silesia had no bishop of its own, but was united with neighbouring dioceses. The upper part of the Oder River formed the boundary of the Kingdom of Poland. The part of Silesia lying on the left bank of the Oder belonged to the territory included in then Bohemia , and was consequently within the diocesan jurisdiction of Prague.
The Bishopric of Prague , founded in , was suffragan to the Archbishopric of Mainz. Casimir I , the son of Mieszko, and his mother were driven out of the country, but through German aid they returned and the affairs of the Church were brought into better order.
He was followed by John —72 , who was succeeded by Piotr I — Pope Adrian IV , at Walter's request in , took the bishopric under his protection and confirmed to it the territorial possessions of which a list had been submitted to him. Bishop Walter built a new, massively constructed cathedral, in which he was buried.
Cyprian —7 was originally Abbot of the Premonstratensian monastery of St. Hedwig , founded the Cistercian convent at Trzebnica. The episcopate of Bishop Wawrzyniec —32 was marked by his efforts to bring colonies of Germans into the church territories, to effect the cultivation of waste lands. This introduction of German settlers by the bishop was in accordance with the example set by Duke Henry the Bearded and Duchess consort St.
