Pope Paul II

Source: http://www.faenumpublishing.com/uploads/2/3/9/8/23987979/hendrickson_et_al._-_platina_paul_ii.pdf page 23

The first sentence of the text in Latin reads: 

Paulus Secundus, Petrus Barbo antea vocatus, patria Venetus, patre Nicolao, matre Polyxena, Sancti Marci presbyter cardinalis, pridie Calendas Septembris pontifex creatur MCCCCLXIIII.

Google translates this as: 

Paul II, has, beard until he was called Peter, his country, a Venetian,

Nicholas father, mother Polyxena, and Mark Cardinal Priest

on the first of September pope created 1464.

So that's pretty cool, we can see the Roman numeral year M.cccc.lxiiii.  We know approximately when this book ("Life of Paul II") was written - in 1479 - and by who - Bartolomeo Platina (aka Bartolomeo Sacchi) who was a medieval historian.  The fact that it was written by a critic of Pope Paul II gives it even more weight.  One odd thing is the date when he become Pope was dated as September 1, 1464, whereas Wikipedia gives it as 30 August 1464.

So this is the earliest "contemporaneously written date" I have yet found.  It seems like it is pretty good proof that Pope Paul II was alive in 1464.

Why is this important?  Because I have the suspicion that at some point in the middle ages that the history of the Catholic church was forged and invented.  Specifically, we have doubts about anything prior to Avignon France in 1309.

According to Wikipedia and older Encyclopedias, we know a lot about history.  But what is the source of it?  Where did the Encyclopedia Britannica, to name one, get its information?

Do we have proof of anything that is older than 1464?