In ancient Rome, that is, in the Empire, not the city, almost everybody who had any education at all spoke Greek. Greek was the language of the educated classes. Only the common people spoke only Latin. It comes as no surprise, then, that the early Church had its liturgy as well as its canon in the same language. The Old Testament had been translated from Hebrew into Greek sometime in the 3rd century B.C., and of course, the New Testament was written in Greek in the first place. Beginning about 200 A.D., several writers began to translate portions of both Old and New Testaments into Latin, and in 382, the then-serving Bishop of Rome (he wasn’t yet being called “the Pope”) tasked a Churchman named Jerome to put the whole thing into a single, coherent Latin text. Jerome used the prevailing Greek text, the Septuagint as his base for the Old, and locally available manuscripts for the New. Jerome’s translation came to be called “The Vulgate”, meaning “The People’s Bible” because it was written in the language of the common people of Rome and Italy. After nearly a thousand years, years during which Latin ceased to be a commonly spoken language at all, the Vulgate was adopted by the Roman Catholic Church as the only appropriate version of the Bible.
The version in use in the Orthodox Church continued to be Greek, of course, for that was the everyday language of the Greek people, including those of Antioch and Constantinople. Syriac continued to be used by the Assyrian Church of the East; Coptic texts were developed for the use of the people of Alexandria and further south; Russian was adopted by the (then) new Russian Orthodox Church, and really there was no question anywhere except in the Roman Church that the Bible should be written in the language of the readers. Still, this became one of the dividing lines between the Roman Church and the reformers of the 15th and 16th Centuries.
Luther translated the Bible into German; Henry VIII had it translated into English. After that, there was no effective way that the Roman Church could ever put the genie back into the bottle. Vernacular translations became the rule of the day, though Rome didn’t actually give up on the Vulgate until the 1960s. Today, Rome urges members to read the Bible daily. In the 1600s, doing so could have gotten you burned at the stake. In fact, the very first English Bible translator, John Wycliffe, having died of natural causes, is said to have been dug up and burned anyway. Fascinating, for Wycliffe’s translation was of the Latin Vulgate, and was essentially no different from it. Another Englishman, William Tyndall undertook another such translation in England a hundred years later, but he went back to the original Hebrew and Greek. He was killed for it too, but later his work formed the basis from which the King James translators worked to produce their epic translation. Even today, we call the King James the “Authorized” Version!