"It was during the Middle Ages that Christianity, in the form of the Roman Catholic Church, became a political power in western Europe. A leader called a bishop headed each major Christian community. By the A.D. 500s, the bishops of Rome, now known as popes, became the leaders of the Catholic Church." Eastern Orthodoxy was, “not under the leadership of the popes in Rome, but rather the emperors in Constantinople.” (Our World Today: People, Place and Issues, Boehm, et. Al, Glencoe/McGraw-Hill (2003), page 241, section "The Rise of Christianity")
