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 poses some problems of interpretation of the information regarding the attack of Margrave Gero on the Slavic tribes, as a result of which he purportedly "subordinated to the authority of the Emperor Lusatia and the Selpuli" (meaning the Słupian tribes) "and also Mieszko with his subjects". According to the majority of modern historians, Thietmar made an error summarizing the chronicle of Widukind, placing the Gero raid there instead of the fighting that Mieszko conducted at that time against Wichmann the Younger. Other sources make no mention of such conquest and of putting the Polans state on the same footing with