Three steps we can take, using experience and intuition, which help to understand that the established historical record is likely to be significantly falsified:
1. observe and acknowledge that deceptiveness is inherent to human communications, including in the historical record
2. understand the strength of motivation for the elites to falsify the historical record
3. recognize that revelations in our age of the degree and frequency of deception by authorities regarding current events can be extrapolated to illustrate the extent of deception dating back many centuries
Indeed, elites pushing agendas have often tried to falsify the historical record. For example, Jew-haters and anti-Zionists have sought to exploit the dubious hypothesis that modern-day Jews are descended from the medieval Khazars, a conjecture which has largely been discredited by historical and scientific research.