The stories of saints’ lives, particularly those who lived several hundred years ago, sometimes mix fact with fiction or folklore.

But the story of the domestication of rabbits, often attributed to some French monks and a papal edict from Pope St. Gregory the Great, was generally considered fact – even by the scientific community.

Until this week.

Widely-accepted legend had it that the domestication of rabbits could be traced to 600 A.D., when some French monks looking to sustain themselves during the cold, meatless months of Lent, took to eating wild fetal rabbits, called laurices.

The meat was allegedly declared acceptable non-meat substance for Lent and Fridays by a papal bull issued by Pope St. Gregory the Great.

But, as it turns out, the bull doesn’t exist, and the whole story may be, well, bull itself.

In a report published this week, researcher Dr. Greger Larson and his colleagues discovered how the hare-brained tale got its start.

“None of it is even close to being true,” Greger Larson, one of the main authors of the report debunking the myth, told the New York Times. “The whole thing is a house of cards,” Larson added. “Why did we never question this? Why were we so willing to believe in this origin myth?”

The researchers went down this rabbit hole by accident – Larson had asked a graduate student, Evan K. Irving-Pease, to do some recon on the rabbit story as part of his research into the domestic origins of dogs and pigs.

After Irving-Pease discovered that no such rabbit-approving papal bull existed, the rest quickly fell apart.

According to the New York Times: “The problem began, (Irving-Pease) said, in 1936 when a German geneticist, Hans Nachtsheim, writing about domestication, said that Saint Gregory of Tours (not Pope Gregory, a different person altogether) had written that fetal rabbits were popular during Lent.

Actually, Saint Gregory merely described one person consuming fetal rabbits during Lent, and that person was sick, died shortly thereafter, and may not even have been a Christian.

Nonetheless, in 1963, another writer, Frederick E. Zeuner, in another book on domestication, added to the mistake and said the fetal rabbits were not considered meat.

“From that point on,” Mr. Irving-Pease said in an email, “the story takes on a life of its own, as further small details get embellished in each retelling.” In the end, he wrote, the “watery” environment of the womb made the fetal rabbits fish, “St. Gregory becomes Pope Gregory and, finally, his manuscript becomes a papal edict.”

The most likely conclusion about the domestication of rabbits, it seems, would be that it was a process that happened over several hundred years, once they began being hunted by humans.

Although the French monks may still be a key part of the story, Dr. Leif Andersson, a senior author of a 2014 paper on the rabbit genome, told the New York Times: “French monks or farmers in Southern France, because they loved rabbit meat, made a specific effort during a period of 50-100 years to establish tame rabbits that became the founding population for the domestic rabbit.”

This may not be the only far-fetched tale misattributed to Pope St. Gregory the Great. Credited with the evangelization of England, legend has it that the Pope was inspired to spread the Gospel in Great Britain after seeing some light-featured English slaves in Rome. According to some accounts, he asked who these slaves were, and someone told him they were Angles. Reportedly, St. Gregory the Great’s response was: “Not Angles, but angels.”