Did the Pope ban blood transfusion in 1678?

This paper concerns an alleged event in the history of haematology that disrupts the otherwise positive narrative of papal encouragement for blood transfusion. It is frequently stated, in popular websites and in the scholarly literature, that when blood transfusion was first developed it was banned by the Pope. However, careful analysis of the sources cited shows this claim to be without historical foundation. There was never any papal prohibition of blood transfusion. It is a myth that needs to be dispelled if the full extent of the Catholic Church's support for blood and organ donation is to be appreciated.