During most of the Middle Ages, the Byzantine Greeks self-identified as "Rhōmaîoi" (, "Romans", meaning citizens of the Roman Empire), a term which in the Greek language had become synonymous with Christian Greeks. The Latinizing term "Graikoí" (Γραικοί, "Greeks") was also used, though its use was less common, and nonexistent in official Byzantine political correspondence, prior to the Fourth Crusade of 1204. While this Latin term for the ancient "Hellenes" could be used neutrally, its use by Westerners from the 9th century onwards in order to challenge Byzantine claims to ancient Roman heritage rendered it a derogatory exonym for the Byzantines who barely used it, mostly in contexts relating to the West, such as texts relating to the Council of Florence, to present the Western viewpoint. The ancient name "Hellenes" was synonymous to "pagan" in popular use, but was revived as an ethnonym in the Middle Byzantine period (11th century).