Ancient history is, first of all, a written history based on the following sources: documents, manuscripts, printed books, paintings, monuments, and artifacts. When a school textbook tells us that Genghis Khan in year XXX A.D or Alexander the Great in the year YYY B.C. have each conquered half of the world, it means only that it is so said in some of the written sources. Seemingly simple questions practically never have clear, unambiguous answers. When were these sources written? Where and by whom were they found? For each of these questions, the answers are very complex and require in-depth research.It is further WRONGLY presumed that there are numerous carefully preserved ancient and medieval chronicles readily available, written by Genghis Khan's or Alexander the Great contemporaries and eyewitnesses to their fantastic conquests, which are kept today in the National Library of Republic of Mongolia or Greece; or in the Library of Congress, or in the private collection of Microsoft. Zilch comma zilch sources come from contemporaries and eyewitnesses: Mongols were a nomad and illiterate bunch, sweet Alexander lived so long ago that most 100% reliable sources know for sure he was the son of Zeus, right? Wrong, we have not seen Alexander's birth certificate, not even a copy, and Zeus doesn't answer the phone. Too bad, only fairly recent sources of information are available, having been written hundreds or even thousands of years after the alleged events. In most cases 'sources' have been written only in the XVI-XVIII centuries, or even later. As a rule, these 'sources' suffered after their discovery considerable multiple manipulations, falsifications, and distortions by editing to this or other order of this or another power in command of the day. At the same time, innumerable originals of ancient documents under a pretext of heresy were DESTROYED in Europe.Of course, some real events were the source of most written documents, even those that were later falsified and manipulated. However, the same real event could have been described in chronicles by authors writing in different languages and having contradictory points of view. There are many cases where such are plainly unrecognizable as the same event.The names of persons and geographical sites often changed meaning and location during the course of the centuries. The exact same name could take on an entirely different meaning in different historical epochs. Geographical locations were clearly defined on maps, only with the advent of printing. This made possible the circulation of identical copies of the same map for the military, navigation, education, and governance applications, etc. Before the invention of printed maps, each original map was a unique work of art, both beautiful, non-exact and contradictory.Mainstream Historians from Oxford say: stop... everybody knows that Julius Caesar lived in the first century B.C. Do you really doubt it? Yes, we really do. For us this statement is only a point of view that is dominant today. But it is only one of many possible points of view until the very fact of his life and deeds is proven. In turn, we will also ask some simple questions: where did you get your information? from a textbook? That's not good enough.Who was the first to say that Julius Caesar lived in the first century B.C.? What book, document and/or manuscript can you quote as a primary source? Who is the author of this source? When and by whom was this primary source written down and where discovered, if you please?As soon as you dig for proof slightly deeper than the school textbook, the adamant grounds for the totally and utterly dominant point of view suddenly evaporate. The whole world community of professional historians will not be able to come with up irrefutable documentary proof that Julius Caesar EVER existed, be it on paper, papyri, parchment or stone. Same story for ALL great names of Antiquity. The proof is unavailable!