First off, I am a Roman Catholic, and due to current circumstances look to the pope as the head of the church. I can not help but feel a constant uneasiness about the catholic perception that the pope is the supreme head. I understand that due to politics, geography, and poor communication that the current state of affairs between West(Catholic) & East(Orthodox) exist. The One True Church is Catholic and Orthodox.
Reading alot of perspectives from both sides, I found this to be the best explanation. It is from the Official Site of the Ecumenical Patriarchate. The following is from it:
By the fifth century the great Christian sees of the Roman (that is the Byzantine) Empire came to number five: one Latin-speaking (Rome) in the West, and four Greek-speaking in the East: Constantinople, Alexandria (founded by St. Mark the Evangelist), Antioch (founded by Peter even before foundation of the see of Rome), and Jerusalem, whose sanctity needs no demonstration since Christ Himself lived and died there. The great importance in this early period of Alexandria, Antioch, and Jerusalem was, however, soon to be diminished by their permanent conquest by the Islamic Arabs in the seventh century. Henceforth, though Orthodox patriarchs continued to exist there (and still do today), ecclesiastical primacy over the Orthodox East inevitably passed to the capital city, Constantinople. But the patriarchs of these "lost" Eastern centers continued in the Byzantine period to be represented at Constantinople by legates (or in person) and sat with the Synodos Endemousa (standing or permanent synod). The latter was actually a patriarchal council which could be assembled at a moment's notice in order to adjudicate any ecclesiastical questions that might arise.
According to the Roman Catholic concept of the Church, the pope, himself one of the five patriarchs (the word "pope" means simply in Greek, "father" or "papas") holds not only titular primacy as primus inter pares (first among equals) over all the patriarchs (a claim always recognized, incidentally, by Byzantine Constantinople), but, from the view of authority and jurisdiction, the right even to intervene and to act as supreme judge in the internal affairs of all other churches. Opposed to this latter theory is the Eastern concept of the "Pentarchy." That is, instead of a papal "monarchy" governing the entire Church, there exists a supreme body of five heads, the patriarchs above named, each of whom exercises jurisdiction over his own ecclesiastical area and who meets together with the other patriarchs in ecumenical councils to regulate matters of dogma and church discipline. This pentarchic theory was firmly established by the time of the Byzantine Emperor Justinian in the mid-sixth century, as is clearly reflected in his nomocanones (combined civil-ecclesiastical law codes).
The link to the site is : http://www.patriarchate.org/book/FIVE_SEES.html