Three of these, led by Fulcher of Orleans, Gottschalk and William the Carpenter respectively, failed to reach even Constantinople.
The armies of Fulcher and Gottschalk were destroyed by the Hungarians in just revenge for their excesses (June); the third, after joining in a wild Judenhetze in the towns of the valley of the Rhine, during which some io,000 Jews perished as the first-fruits of crusading zeal, was scattered to the winds in Hungary (August).
But the controversy about predestination, which, in the 9th century, Hincmar and Hrabanus fought out with the monk Gottschalk of Fulda, as well as the discussions that arose from the definition of the doctrine of transubstantiation of Radbert, enable us to gauge the intellectual energy with which theological problems were once more being handled.
So far as we can learn, however, Erigena's orthodoxy was not at the time suspected, and a few years later he was selected by Hincmar, archbishop of Reims, to defend the doctrine of liberty of will against the extreme predestinarianism of the monk Gottschalk (Gotteschalchus).
The doctrine of Augustine was revived in the 9th century by Gottschalk, who taught that God's passing over the lost meant their predestination to punishment.
In the controversy about election, when appealed to by Charles the Bald, Ratramnus wrote two books De praedestinatione Dei, in which he maintained the doctrine of a twofold predestination; nor did the fate of Gottschalk deter him from supporting his view against Hincmar as to the orthodoxy of the expression "trina Deitas."
His first encounter was with the heresiarch Gottschalk, whose predestinarian doctrines claimed to be modelled on those of St Augustine.
For a part at least of his doctrines Gottschalk found ardent defenders, such as Lupus of Ferrieres, the deacon Florus and Amolo of Lyons.
Through the energy and activity of Hincmar the theories of Gottschalk were condemned at Quierzy (8J3) and Valence (855), and the decisions of these two synods were confirmed at the synods of Langres and Savonnieres, near Toul (859).
To refute the predestinarian heresy Hincmar composed his De praedestinatione Dei et libero arbitrio, and against certain propositions advanced by Gottschalk on the Trinity he wrote a treatise called De una et non trina deitate.
Gottschalk died in prison in 868.