On 29 June 1524 the humanist, doctor of both sciences and Tallinn and Tartu bishop became the new Riga's archbishop. Blankenfeld had been earlier the procurator of the German order in Rome and thus he had good relations with the pope.
Thanks to the latter he could become the head of the three knighthoods in Livonia.
Blankenfeld had been the active supporter of the old religion already before becoming the archbishop, being able to foil the first reformation attempt in Tartu. Now, after becoming Riga's archbishop, he tried to organize this also in whole Livonia.
This was still a failure for him, he had a conflict with the cities: on 21 August 1524 the city of Riga cancelled his loyalty oath and wished to give him under sole power of the order. The grandmaster Plettenberg still first refused from it.
The moods against Blankenfeld and Catholicism increased also in Tallinn so that at the end of 1524 he found it better to give up the position of Tallinn bishop. In 1525 the circumstances still intensified when the war conflict rose in Tartu between the citizens and bishop men.