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). While in the West the term "Roman" acquired a new meaning in connection with the Catholic Church and the Bishop of Rome, the Greek form "Romaioi" remained attached to the Greeks of the Eastern Roman Empire. The term "Byzantine Greeks" is an exonym applied by later historians like Hieronymus Wolf; "Byzantine" citizens continued to call themselves Romaioi (Romans) in their language. Despite the shift in terminology in the West, the Byzantines Empire's eastern neighbors, such as the Arabs, continued to refer to the Byzantines as "Romans", as for instance in the 30th Surah of the Quran (Ar-Rum). The signifier "Roman" (Rum millet, "Roman nation") was also used by the Byzantines' later Ottoman rivals, and its Turkish equivalent Rûm, "Roman", continues to be used officially by the government of Turkey to denote the Greek Orthodox natives (Rumlar) of Istanbul, as well as the Ecumenical Patriarchate of Constantinople (, "Roman Orthodox Patriarchate"). Among Slavic populations of southeast Europe, such as Bulgarians and Serbs the name "Rhomaioi" (Romans) in their languages was most commonly translated as "Greki" (Greeks). Some Slavonic texts during the early medieval era also used the terms Rimljani or Romei. In medieval Bulgarian sources the Byzantine Emperors were the "Tsars of the Greeks" and the Byzantine Empire was known as "Tsardom of the Greeks". Both rulers of the Despotate of Epirus and the Empire of Nicaea were also "Greek tsars ruling over Greek people". Equally, among the Nordic people such as the Icelanders, Varangians (Vikings) and other Scandinavian people, the "Rhomaioi" (Romans) were called "Grikkr" (Greeks). There are various runic inscriptions left in Norway, Sweden and even in Athens by travellers and members of the Varangian Guard like the Greece runestones and the Piraeus Lion which we meet the terms Grikkland (Greece) and Grikkr referring to their ventures in Byzantine Empire and their interaction with the Byzantines. Society While social mobility was not unknown in Byzantium the order of society