He studied law in Bologna and was private secretary to the papal Curia, then stood as a soldier in the service of Emperor Maximilian I. Under Margrave Albert of Brandenburg-Ansbach, the Grand Master of the Teutonic Order, he came to Königsberg.
He was the first Lutheran bishop. Polentz was confirmed as Bishop of Samland by the Curia in 1519. Johann Briesmann taught him Hebrew and the teachings of Martin Luther.
Polentz was regent of Prussia during the absence of Duke Albert from 1522 to 1525.
He worked together with the lawyer Erhard of Queis, the Bishop of Pomesania. He gave his first Lutheran sermon at Christmas 1523 in Königsberg.
When Albert gave his approval, bishop Polentz launched the Reformation in Prussia. Polentz implemented the Prussian Church Order.
The Church Order provided for visitations of the parishioners and pastors, first carried out by Polentz in 1538.
Georg of Polentz married in 1525 and after the death of this first wife, again in 1527.
Polentz was a member of an old Saxon noble family.
