[drybjed]

What do you mean? Catcholic Church has records, did they just came up with something about a nonexistent Pope Joan out of thin air? How could they...

[rsynnott]

Catholic Church's records on early popes are often surprisingly bad, particularly in antipope-heavy eras. There are a _number_ of popes where the detail is pretty vague. Use of damnatio memoriae also confuses the issue, eg: https://en.wikipedia.org/wiki/Pope_Formosus#Legacy

[karel-3d]

eh not really, we NOW have quite good records on most popes except for the first few ones that we get just in a list from St Irenaeus (for example from St Linus - the guy immediately after St Peter - we get almost nothing)

but about the middle age popes we know quite a lot NOW. But it used to be different.