It's a broad sort of deal. History is at its most butchered state when those with political axes to grind come to town. Nothing is safe from being mutilated and twisted and rewritten according to whatever prejudice is at hand. Famously, it's been said that the best political litmus test in America is to ask someone why the Roman Empire fell. If they answer that it was overrun by barbarians flooding in from without and destroying it from within, you can bet fairly safely they are anti-immigration, or answering that changing climate and immigration policies are the big factor will likely be very environmentally-concerned in politics, for example. But a simple bias like that is just the beginning and things can get much worse. Details are always sketchy; it's the broad swipe that's key to these narratives. Afterall, dwelling on details will inevitably bring up those pesky questions that threaten the uniformity. All needed context is simply modern politics.

This kind of behavior is common to Islamophobes, Antisemites, Occidentialists and plenty of others. Historical sins and actions are rehabilitated to always be the fault of the group at hand. Those terrified of the waves of Muslims pouring in will see Mideastern history since the advent of Islam as a monolithic block of Muslimness sweeping out and slaughtering everyone else, and seeking to get in and end civilization. Islam has always been the same, and it's always been what I am most scared of in it regardless of historical context and anything of the last century-wroth development of Islamic political thought and militant Salafism. Antisemites will paint the Jews at every stop and every century as conniving to run everything. Again, details and dogma-busting context are unimportant. Nevermind why the Jews were in the banking sector; they have their fingers all over the money. Less savvy amongst the Arab 'resistance' or self-declared 'anti-imperialist' crowd will blame anything that has gone wrong in the history of Arab civilization on the West. The imperialists are responsible for holding us back, for dividing us, for conspiring to domineer everything. Nothing is broken from within.

History becomes just another tool in the arsenal of agenda and fear. It's sad. History is rewritten by the hatemongers.