[2] In 1335, Pope Benedict XII appointed Gallus de Novo Castro as inquisitor for the region around Prague with the goal of converting heretics.

In 1339, he travelled to Avignon to confer with Benedict on future action, bringing with him Ulrich (Oldřich) III, lord of Hradec.

In a bull dated 6 March 1340, Benedict XII formally granted the same indulgence to those who took part in Ulrich's punitive expedition as they would obtain pilgrimage to the Holy Land.

Benedict XII, responding to a request from King Casimir III of Poland, ordered the crusade preached in Bohemia.

[5][6] According to Galvano Fiamma, King John the Blind of Bohemia joined the defence of Poland.