The Spread of Christian Ideas

As the Roman Empire divided, Christianity divided as well.  In the Western Roman Empire, the Christian Church became the Roman Catholic Church headed by the pope.  In the Eastern Empire (referred throughout this post as the Byzantine Empire), the Christian Church became the Eastern Orthodox Church headed by a patricarch appointed by the Byzantine Emperer.  The two churches became ever divided due to differences over the use of icons, the authority of the pope, and ultimately, the willingness of each church to come to the aid of the other.  Furthermore, the pope gave the Frankish king Charlemagne the title of emperer, which was a "slap in the face" to the Byzantine Emperer.  After centuries of tension, the pope excommunicated the patriarch, and the patriarch excommunicated the pope.  The split between the two churches still exists today.  More details of what is now known as the Great Schism can be found at http://en.wikipedia.org/wiki/East%E2%80%93West_Schism