[markomalley]

The key person you need to be familiar with is Berengarius of Tours. His heresy (denying a change in the bread and wine into the Body and Blood of Christ) resulted in this decree of the Lateran council 4 (this was, apparently after local councils in 1073 and 1078, where Berengarius recanted his position, did not finally resolve the heresy).

But, as with all Church Councils since the Council of Jerusalem, as recorded in the Acts of the Apostles, these were held, not to establish some sort of doctrine, but to resolve controversies that crop up.

[wagglebee]

Those who continue to embrace these heresies (and as I mentioned before gnostic denial of the Real Presence, and a synthesis of Arianism and Nestorianism is endemic among Protestants), seem to believe that nothing existed before the Church addressed it formally.

This belief that Transubstantiation was unknown before the 13th century is laughable when you consider that the Orthodox also accept it as dogma and the Great Schism was in 1054.