All languages that bring cultures together are artificial. Whether through free exchange or imperial domination, the connecting language is not anyone’s vernacular. It may be an offshoot of a given vernacular, but it ends up being something else. Each historical region has its history of such languages. In Europe, Greek first, and then Latin, provided what scholars would later call a lingua franca, a bridge language used to make communication possible between peoples speaking different and non-mutually intelligible languages. Koine Greek was the first identifiable common, or vehicular, language (koine means common in ancient Greek), and dominated Europe during the Hellenistic and ancient Roman period. In the medieval West, Latin replaced it, especially among the cultured, most often ecclesiastical, elites.
Communication depended on a bridge language to cover increasingly larger populations and cultures. Latin enabled cultural exchange across disparate cultural areas. Latin served the spread of ideas through books, of human capital through exchange networks, monasteries, churches, schools, universities, chanceries, etc, and of science by providing a language common to all engaged in theoretical, speculative or experimental science.
Only that Latin was no-one’s mother tongue. It wasn’t a vernacular language, characteristic of an indigenous population (from the Latin vernaculus for domestic or indigenous). When people say that Latin is a dead language, they often refer to the artificial idiom which persisted, in many areas, until the end of the 19th century. This language isn’t dead because it was never alive. At least not alive in a spoken language sense. The Latin that midwifed Europe is not the Latin of Cicero or Virgil, but the vehicular language of medieval and early-modern Europe. And this was more akin to computer code than human language – an artificial construct based on natural language (this artificial Latin was a product of literary, and therefore written, classical Latin, just as computer code is a product of algorithm and formal logic).
When European vernacular languages such as English, French, Italian, German, achieved literary status, this Latin idiom was recognised for what it really was: code. A functional, tongueless tongue, formalised to the limit, open-sourced and truly in the public domain. Kepler, Galilei, Newton and Linnaeus published their works in Latin, which is to say in code. Europe was born on a bridge, and the bridge was made of Latin.