Several historians have concluded that the prophecy is a late 16th‑century forgery. Saint Bernard of Clairvaux, a contemporary biographer of Malachy who recorded the saint's alleged miracles, makes no mention of the prophecy. The earliest known reference to them dates to 1587. Spanish monk and scholar Benito Jerónimo Feijóo y Montenegro wrote in his "Teatro Crítico Universal" (1724–1739), in an entry called "Purported prophecies", that the high level of accuracy of the verses up until the date they were published, compared with their high level of inaccuracy after that date, is evidence that they were created around the time of publication. The verses and explanations given by Wion correspond very closely to a 1557 history of the popes by Onofrio Panvinio (including replication of errors made by Panvinio), which may indicate that the prophecy was written based on that source. In 1694, Claude-François Menestrier argued the additional interpretive statements were not written by Ciacconius, as the prophecy was not mentioned in any of Ciacconius' works, nor were the interpretive statements listed among his works.