Depending on who writes it, depending on current trends, a people, a society becomes strong or weak.
When strong, those out of favour are savages, their power disparaged. When weak, they are turned into slaves.
When the society is held in high regard, the leaders are heroes. When no longer powerful, their once ‘Greats’ are exposed as murderers, tormentors. rapists.
Although information is available, and always has been, how it is utilised, when and where, depends on who or what holds power.
So much information is suppressed so that the current ‘narrative’ can persist.