Dan Quayle? Is that you?
Yes, the Ancient Romans spoke Latin. Latin is the root of the Romance Languages (Italian, Spanish, French, Portuguese, among others) and, via Norman French, had a large impact on English as well. (English is a Germanic language that had a lot of input from Old Norse early in its history, with the French coming in after 1066 and William the Conqueror.) I don’t know how you got taught that it was artificial, but it certainly is not. It was a living language and Italian is its lineal descendant.
It is now a mummified language which is kept functional for the purposes of the Roman Catholic Church by the addition of new words but is otherwise left unchanged. It was preserved through the Middle Ages and Renaissance after the fall of Rome (400-600 AD to roughly 1500, then the Renaissance was 1500 through 1800 when the Industrial Revolution happened in a big way)* to serve as the common language of everyone rich enough to have learned it in school. Copernicus, Kepler, Galileio, and Newton all published their works in Latin so they could be read throughout the civilized (that is, European) world.
It was taught in high school and college as part of a ‘liberal education’ because people thought it was ‘improving’. That is, they thought it made you better in some immeasurable way. More rationally, they also thought it helped you learn English grammar.** That notion and practice held on well into the 20th century.
*(All dates horribly simplified. 410 is when the Roman Empire ended in England, a rather far-flung province. It lasted longer in Rome itself. 1500 is when the back of Catholic domination was broken by Lutheranism and the New World was open to large-scale exploitation/exploration/immigration. I’m not going into the huge changes between 1500 and 1800 in such a small post.)
**(Less rationally, they thought ‘correct’ English should conform to Latin rules. Obvious nonsense, and the source of obviously nonsensical rules against splitting infinitives (“To boldly go…”) which is impossible in Latin but often good style in English.)