I would answer your question the same way Jay did, where is your papal supremacy taught in the 1st 1000 years?

You realize that all the different ethnic churches have the same doctrines and dogmas right? There are numerous orthodox churches near me, whether I go to the Aniochian Church, the Greek Church, or OCA Church, the same exact service will be being conducted. The little OCA mission Church I attend was started by a Greek Church, monks and nuns from the Russian monastery down the street regularly attend our services. So what exactly is your point about there being different ethnic Churches?

Just how depraved does the catholic church have to get before you start to question its legitimacy?