Medieval crusade advocates fabricated prophecies to promise certain victory.

Evidence

After a disclaimer that he will not prophesy since he is neither a prophet nor the son of a prophet, Fidentius tells of a book called the Liber Clementis: a book of prophecy containing discussions between Jesus and Peter, written in Greek, translated into Arabic, and brought to Fidentius by a Syrian monk. … This same book, Fidentius says, contains the following prophecy of Christian victory: “There will come,” said Christ, “a lion cub, and he will liberate the Christian people from the hands of the sons of the wolf, and he will overcome them and force their remnant into the desert from which they came, and the Christians will subjugate the sons of the wolf for forty times beyond that which the sons of the wolf subjugated the Christians. — John V. Tolan, Saracens, 1087

Categorization

• QUESTION: The alleged Liber Clementis — Jesus-Peter dialogues in Greek then Arabic — sounds like a known apocryphal text or a pure invention; worth identifying whether Fidentius fabricated it or drew on an existing apocalyptic tradition.