Colloquy of Oldersum

The document Ulrich subsequently wrote about the debate was widely distributed and thus contributed to the rapid establishment of Protestantism in East Frisia[1].

Only shortly after the reformer Martin Luther published his 95 theses in Wittenberg on October 31, 1517 in response to Johann Tetzel's indulgence sermon, the Protestant doctrine was accepted in East Frisia.

As early as 1519, the Oldersum pastor Hinrich Arnoldi is said to have held services according to the Protestant confession, like Heinrich Brun in Aurich.

Ulrich, who had come into possession of half of the castle and lordship of Oldersum through marriage in 1494, initiated and organized the public debate between the preacher Georg Aportanus from Emden and the Catholic Dominican prior Laurens Laurensen from Groningen in June 1526.

Due to the influence of the Calvinists, especially John Calvin and Huldrych Zwingli, the vast majority of western East Frisia has since become Protestant-Reformed[1].