The population of the Byzantine Empire, at least in its early stages, had a variety of mother tongues including Greek. These included Latin, Aramaic, Coptic, and Caucasian languages, while Cyril Mango also cites evidence for bilingualism in the south and southeast. These influences, as well as an influx of people of Arabic, Celtic, Germanic, Turkic, and Slavic backgrounds, supplied medieval Greek with many loanwords that have survived in the modern Greek language. From the 11th century onward, there was also a steady rise in the literary use of the vernacular.