https://en.wikipedia.org/wiki/Historian

Systematic historical thought emerged in ancient Greece, a development that became an important influence on the writing of history elsewhere around the Mediterranean region. The earliest known critical historical works were The Histories, composed by Herodotus of Halicarnassus (484 – c. 425 BCE) who later became known as the "father of history" (Cicero).

Now how many people had access to this knowledge is another matter, but studying history and learning from it was an important aspect in the education and training of leaders to be since more than a thousand years at the very least.

If we look at Moses and the Pharaoh as well as ancient Greek democracies, we can conclude that the principles of politics have not changed all that much in the past 3000-4000 years of human history. The knowledge was always there and the same mistakes are always repeated, with some very incremental progresses and regressions in between.