In 1497, two years after the Duchy of Płock was incorporated into Poland, the Bishop of Płock, Piotr Chotkowski, died. King Jan Albert wanted his successor to be vice-chancellor Grzegorz von Lubraniec. However, due to his advanced age, he recommended his nephew Jan Lubrański, the royal secretary, to this office. On November 6, 1497, the Archbishop of Gniezno, Fryderyk Jagiellończyk, was elected bishop of Płock - as a result of the vote chosen by the chapter of Mikołaj Bartnicki. He, in turn, suggested Jan Lubrański. It seems that this choice had already been agreed upon with some of the canons and Mikołaj Bartnicki. On election day, Jan Lubrański was in Gdańsk as a royal envoy. Later he stayed permanently at the royal court. On April 21, 1498, with the king's protection, he became bishop of Poznań, but until the end of that year he used the title of bishop of Płock and held this office. As the bishop of Płock, he contributed to the foundation of the Observant monastery in Skępe. The election of Jan Lubrański as bishop of Płock was in many respects of key importance for this diocese, and above all, it initiated the process of uniting the country and the Płock diocese with the Kingdom of Poland.