Jews driven into the Danube and forcibly baptized en masse; Henry IV would later permit them to return to Judaism

At Ratisbonne, on the Danube, the crusaders did not kill: they baptized. The entire community was driven into the river and baptism pronounced over it en masse, according to a rite that nothing rendered valid even in the eyes of canon law itself.

The emperor Henri, returned from Italy, authorized the forcibly converted people of his lands to return to Judaism. The antipope Clément reproached him for it, invoking the principle that baptism, even when improperly administered, cannot be undone. The emperor overrode him.

Ratisbonne thus became Jewish again without having been destroyed, which made it one of the rare communities of southern Germany to pass through the First Crusade without a break. It sheltered in the following century Ephraïm de Ratisbonne, whose *Livre du souvenir* records the persecutions of the time.