Mieszko I Tanglefoot in 1163, and thanks to the intervention of the Emperor Frederick Barbarossa, Mieszko and his older brother Bolesław I the Tall returned to Silesia. Mieszko and Bolesław I the Tall co-ruled the Duchy of Wrocław during the period 1163–1173. At first, their rule did not extend over the major Silesian cities, which remained under the control of Bolesław IV the Curly, the current High Duke of Poland. The brothers retook them in the year 1165, taking advantage of Bolesław IV's involvement in a crusade against the Prussians. However, soon Mieszko began his efforts to obtain his own Duchy, maybe in
Mieszko I of Poland of the Polish towns like Gniezno or Ostrów Lednicki. The belief that the baptism was accomplished through the Czechs in order to avoid the dependence on Germany and the German Church is incorrect, because Bohemia would not have its own church organization until 973. At the time of the baptism of Mieszko the existing Bohemian church establishment was a part of the Regensburg diocese. Thus, if the Polish ruler accepted the baptism through Prague's mediation, it had to be sanctioned in Regensburg. However, the religious vocabulary (words like baptism, sermon, prayer, church, apostle, bishop or confirmation) were adopted from the