Every great civilization has its humble beginnings!
Legend says that Rome was founded by Romulus, twin of Remus, who then became the first King of Rome. I won't elaborate on the legend since it has very little historical foundation. As a matter of fact, Romulus may not have existed at all, as we will see at a later date when I talk about the historicity of events in the Republic.
Thus, according to legend, Romulus established the very principles on which the entire Republic is based! And all of this around 750 BC.