Background
His parents were Charles I of Münsterberg-Oels and Anna of Sagan, daughter of Duke John II "the Mad" of Żagań.
Duke of Münsterberg Duke of Oels
His parents were Charles I of Münsterberg-Oels and Anna of Sagan, daughter of Duke John II "the Mad" of Żagań.
He also held the title of a Count of Kladsko/Glatz, though he never ruled Kladsko. From 1545 to 1560 he was Bishop of Brandenburg. At the instigation of his father, Joachim was brought up in 1515–1517 by Johann Hess, who at the time held a canonicate in Nysa.
In a joint deed dated 25 June 1535, they awarded the city of Srebrna Góra/Silberberg, which belonged to Münsterberg, the status of free mining town.
In 1537, they expelled the Catholic priests from Münsterberg/Ziębice and appointed a Lutheran vicar. In the same year, Elector Joachim II of Brandenburg promised Joachim in Bautzen the bishopric of either Lebus or Brandenburg, when one of these would be available.
John continued to rule the Duchy of Oels and Henry II ruled until 1548 part of the Duchy of Bernstadt. With this appointment, Joachim also received the rank of an imperial prince, and was thus equal in rank to the Margrave of Brandenburg.
In 1560 he abdicated the secular rule of the bishopric, in favour of the elector"s son, prince John George.
After Elector Joachim"s death in 1571, the secular rule of the bishopric was incorporated into the electorate.
Joachim was a member of the Münsterberg branch of the Bohemian noble Poděbrady family.