Languages of the Ottoman Empire
The language of the court and government of the Ottoman Empire was Ottoman Turkish, but many other languages were in contemporary use in parts of the empire. Although the minorities of the Ottoman Empire were free to use their language amongst themselves, if they needed to communicate with the government they had to use Ottoman Turkish.
List of lingua francas
During the time of the Hellenistic civilization and Roman Empire, the lingua francas were Koine Greek and Latin. During the Middle Ages, the lingua franca was Greek in the parts of Europe, Middle East and Northern Africa where the Byzantine Empire held hegemony, and Latin was primarily used in the rest of Europe. Latin, for a significant portion of the expansion of the Roman Catholic Church, was the universal language of prayer and worship. During the Second Vatican Council, Catholic liturgy changed to local languages, although Latin remains the official language of the Vatican. Latin was used as the language of scholars in Europe until the early 19th century in most subjects. For instance, Christopher Simpson's "Chelys or The Division viol" on how to improvise on the viol (viola da gamba) was published in 1665 in a multilingual edition in Latin and English, to make the material accessible for the wider European music community. Another example is the Danish-Norwegian writer Ludvig Holberg, who published his book "Nicolai Klimii iter subterraneum" in 1741 about an ideal society "Potu" ("Utop" backwards) with equality between the genders and an egalitarian structure, in Latin in Germany to avoid Danish censorship and to reach a greater audience. Newton's Philosophiæ Naturalis Principia Mathematica was published in Latin in 1687: the first English translation did not appear until 1729. In subjects like medicine and theology Latin has been a subject of study until the present day in most European universities, despite declining use in recent years.