Since the Middle Ages, Europe has seen Christianity as central to its Western identity. While true, many beliefs and ideas shaping Europe - including Christianity - originate in the Orient. Long before the birth of Jesus, Judaism spreads across the Roman empire; Muslim Moors dominate the Iberian Peninsula from the 8th to 15th centuries. The churches of East and West schism, only to periodically reunite in crusades against the common Muslim threat. The Church splinters further in the Reformation.