We typically have extremely limited history of any civilization that didn't have a pervasive and resilient writing system. A lot of cuneiform clay tablets survi

We typically have extremely limited history of any civilization that didn't have a pervasive and resilient writing system. A lot of cuneiform clay tablets survive, for example, because they were in a library in a city that burned and that burning baked the clay. Fun fact: there are an estimated 500,000 to 1 million cuneiform tablets sitting in museums around the world. Less than 10% have ever been translated. Papyrus was another medium for the written record in ancient times and it doesn't tend to survive long. Longer lasting materials only really came about centuries later when vellum and longer lived paper. So any papyrus works only tended to survive because they were repeatedly copied. As to roman's eradicating history, let me add thsi context: the origins of Rome itself is largely unknown. Rome was sacked by the Celtic Gauls in (IIRC) the 4th centure BCE so now we have legends that are more likely fiction than fact and may well just be apocryphal (eg Romulus and Reemus). Reconstructing something as well-known (at the time) as the Twelve Tables was a significant effort. Also consider that before the Romans there were the Etruscans. Not much is really known about them at all. They had their own language including a written language but it's never been deciphered as we simply don't have enough samples. Those we have are typically from burial sites. IIRC one of the more significant fragments was found because an Etruscan manuscript was used in wrapping a mummy. So my point is that histories don't tend to survive, even for the conquerors, so a claim about eradicating history needs a lot of supporting evidence.