Pope military aid from Pope Urban II in the ongoing Byzantine–Seljuq wars. Urban, at the council of Clermont, called the First Crusade to assist the Byzantine Empire to regain the old Christian territories, especially Jerusalem. With the East–West Schism, the Eastern Orthodox Church and the Catholic Church split definitively in 1054. This fracture was caused more by political events than by slight divergences of creed. Popes had galled the Byzantine emperors by siding with the king of the Franks, crowning a rival Roman emperor, appropriating the Exarchate of Ravenna, and driving into Greek Italy. In the Middle Ages, popes struggled with
Religious war expansion into Asia Minor and Europe proper. Later, Crusades were launched against other targets, either for religious reasons, such as the Albigensian Crusade, the Northern Crusades, or because of political conflict, such as the Aragonese Crusade. In 1095, at the Council of Clermont, Pope Urban II raised the level of war from "bellum iustum" ("just war"), to "bellum sacrum" ("holy war"). In 16th-century France there was a succession of wars between Roman Catholics and Protestants (Hugenots primarily), known as the French Wars of Religion. In the first half of the 17th century, the German states, Scandinavia (Sweden, primarily) and Poland