Latin was an Indo-European language spoken in Latium, the region immediately surrounding Rome.
It is thought to be part of a linguistic culture once spread on a wider area and subsequently reduced in size due to a more recent migration of other Indo-European people who brought into the Italian peninsula the so called "Italic languages".
In the first century b.C. the Roman citizenship was granted to the other Italic people and this led the republic to obvious social changes; it is then that in Rome first arose the concern for the purity of the language.
The expansion of the Roman Empire eventually spread Latin throughout Europe and the Mediterranean. Eventually, when the Empire fell, Vulgar Latin began to dialectize, based on the location of its various speakers. Vulgar Latin gradually evolved into a number of distinct Romance languages such as Italian, French, Spanish, Catalan, Portuguese and Romanian; the differences between them growing greater and more formal over time.
Out of the Romance languages, Italian is generally considered the purest descendant of Latin in terms of vocabulary, though Romanian more closely preserves the classical declension system.

Latin survived throughout the middle-ages as Lingua Franca among the well-educated elite, especially in ecclesiastic and academic environments, although by the time of widespread Christian conversion in Europe, Latin had already become more a language of the Church and of scholars, rather than of the commoners and it was no longer the language spoken by Caesar, Virgil, Ovid or Tacitus.

Although now widely considered a dead language, with very few fluent speakers and no native ones, Latin has had, as we said above, a significant influence on many other languages still thriving today, including English. In fact English is Germanic in grammar, Romance in vocabulary and the 60% (but some says 80%) of its vocabulary has its roots in Latin. In the medieval period much of this borrowing occurred through ecclesiastical usage.

Pronunciation

As you can imagine, in three thousands years the language evolved and inevitably did so also its pronunciation…
In this section we will not explore the entire evolution of it, rather we will try to concentrate on the period we depict.
It is curious to know that the Latin alphabet derives from the Etruscan one, which derives from the Greek, which derives probably from the Phoenician.
These were the letter of the Latin alphabet:

A B C D E F (G) H I L M N O P Q R S T V X (Y) (Z)

The letter "Y" and "Z" were introduced only at the end of the Republican Age (in the mid first century b.C.) to transpose Grecian phonemes that did not exist in Latin. The letter "K" was sometime borrowed but almost always converted into "C".
The letter "G" was introduced in the 3rd century b.C. as a modification of "C".
The consequence of this dragged further in time and this is the reason why Gaius Julius Caesar is sometimes spelt in the old fashion Caius Julius Cesar and similarly Gaius Marius is sometime known as Caius Marius (just to mention the most famous examples).
Although, the above spelling is rather recent, in fact, as you can see from the list of letters, the letter "J" and "U" simply never existed until the Middle Ages, also all the letters where majuscule since the minuscular is another early medieval innovation.
That known, it comes without saying that when Caesar himself had to write his own name he would have written "GAIVS IVLIVS CAESAR" and it is for this reason that the LEGIO OCTAVA AVGVSTA was devoted to "AVGVSTVS" rather than to "Augustus" hence the abbreviation "AVG".

The simplicity of learning how to pronounce Latin lies in the fact that, unlike in English, each letter has always the same sound, regardless if it is in the beginning, the middle or the end of a word (with "H" as the only one exception), therefore a double letter means you have to prolong that very sound but not modify it.
Let's now have a brief look on how to pronounce the single letters:

The difference between CVI and QVI is that the former is pronounced like "koo-ee" with the stress on "oo"; the latter, instead, like "kwee" with the stress on "ee".

So if you had asked the conqueror of Gaul himself what his name was, he would have never answered "Djoo-lee-oos See-sar" but rather "Ee-oo-lee-oos Ka-eh-sar".

It is important to scan the letter "R" in order not to stumble in misunderstanding such as this:
If you say "pee-lah porr-tah-teh" it would be pila portate meaning "carry the spears" but if you say "pee-lah po-tah-teh" it would be pila potate meaning "trim the spears".