The Liber Tempest was a seventy-seven volume tome describing the deeds of the Storm Wardens and the lives of its heroes throughout the troubled years of the Age of Apostasy in 945.M36. It was authored by Chief Librarian Brin Maxen, who had been so crippled that he could no longer provide his service to the Chapter. It is claimed that Maxen held his own death at bay for nearly twelve years as he recited the text to his disciples.
After his death, it was discovered that there were several version of the text, which nearly led to a schism within the Chapter. When the texts were studied in detail, it was discovered that they differed in several major details. These differences were so great that Maxen's successor came to suspect that an outside agency had corrupted the transcription process or perhaps interfered with the archives at a later date. In response, the senior Librarians undertook a study of each text to see which, if any, version contained the real events. This would take the better part of a century. Eventually a single text was chosen as the truth and the remaining versions were sealed away in the Librarium. Each apocryphal text was named after the Librarian who had compiled it, such as the Apocrypha of Yorath, the Book of Einion, and the Liber Esoterica Cadfanius.