Al qaeda and the Taliban are both related to the terrorism in afghanistan
The Great Schism - separation of the Orthodox and Catholic church into two churches, each promoting a different 'brand' of christianity
Political separation and tension between Eastern and Western Europe, as countries picked which church to follow
Creation of the title Ecumenical Patriarch for the head of the Orthodox church.
Raised tensions between Byzantium and Rome.
etc.
Chief Justice of the U.S Supreme court