Any way for the Patriarch of Constaninople to excommunicate the Pope?

Just to give him a test of his own medicine. ~D

Well, I think it actually happened twice in real life. Once during the Photian Schiszm (before game time in 860, I think) and once during the Great Schiszm (1054). There are several mistakes regarding the Orthodox factions in the game. The Byzantines would not use the cross depicted on their shields. That is a Russian Orthodox cross. The Greek Orthodox Cross has four equal arms, like "+" on their churches. If I wee the game designed, I would have picked a Chi Rho Cross (used by Constantine the Great) or some kind of double headed eagle for the Byzantine shields. I reality, armies of Constantinople marched off to war under a banner depicting the Icon of the Theotokos (Virgin Mary).
Of course the terms Byzantine and Byzantium would have been foreign to the people of the empire of Constantinople. They thought of themsleves as being Romans (Romaoi) and even the Latins referred to their land as Romania. Byzantinium is primarily an construction of 17th century western European historians.

When Constantine the XI threw off his Imperial regalia and joined in combat to the death with a body of Janissaries on 29 May 1453, he was in fact the last Roman emperor in a line that descended from the great Agustus.

Also the Russian cathedals and buildings buildings sporting the "Onion" domes used as pictures for the games buildings were later architectural designs. Orthodox cathedrals in the Medieval period would have had domes like the one atop Hagia Sophia in Constantinople.

In game terms: no. But the Orthodox don't accept the Pope as ruler and the Catholics don't listen to the Roman Emperor anyway, it is a rather futile excercise.

Perhaps you should try playing as the Papal faction.

but sure,

all you have to do is drop a big violet and violent wights army over rome- province and the patriach of rome, will, finally!!!!, silence..(for god`s sake)

i changed my startpos(like most) so the sicilian(arag) start with a couple florins more. everytime it should be..patriach of rome takes naples, it`s different. both factions start a *endless* discussion. don`t bother the *game* anymore.