I have heard that there are 5 main Patriarchs: The Patriarch of Rome, Constantinople, Antioch, Alexandria and Jerusalem. What's exactly their role? Is there an uniformity belief about them among Traditional Christians?
That was the condition of the Church at that point in time (minus those who had been separate since Chalcedon) - as our brother
@dzheremi said.
Rome separated in 1054 (the Great schism) and became Catholicism.
The other Patriarchs continued, and through Orthodoxy having been spread through the world, there are more now (Russia became Christian soon after that point, for example).
It's not something I concern myself with overmuch - I think there are now 7 Patriarchs? - but I could be wrong. It has to do with which parts of the Church govern themselves.
In actuality ALL bishops are equal. They just have different areas of responsibility.
And this really only relates to the Eastern Orthodox Church.
Luther for example contacted the Patriarch (of Constantinople iirc) but communication was exceeding slow in those days and by the time a few missives had been exchanged (a few years), Luther had developed his theology to an extent he didn't wish to recant and it was incompatible with Orthodoxy on some counts, so the Patriarch asked they simply view each other in fellowship. But Luther was never in communion with any of the Orthodox sees, and neither had any other Protestant been. So it's not directly relevant, I suppose, to those outside of Orthodoxy.
We do maintain those ancient sees though, and they still have communion with one another. The Churches mentioned in Scripture mostly still exist and are still a part of those same sees. It's just a structure of Church oversight.