"History is the lie commonly agreed upon." Voltaire was responsible for this quote. Does this mean that everything we know about our history is a lie? Well no not really. As stories go through time and travel to different places, things are bound to change a bit. In the end, history depends on how it was reported, and how people describe it even though it migh not be the whole truth.
To give the best possible example, think of the game telephone. Almost always when the message gets to the end it has changes drastically. It does not happen intentionally but does anyways. Especially in older history when we didn't have as many things documented we had to rely on what eyewitnesses said and people at the time of the event. So when enough people say the same version of the story, even when it is not the complete truth, it is then believed to be the truth even when it is not. For instance the story of the pilgrims we believe to be true is not in actuality. The only reason we do think this event happened the way it did is the people of the U.S agreeing to the same lie because it is close enough to the truth and is much nicer than reality.
Although much of history is filled with lies, there is a lot of truth in there too. We can be given the facts but it is up to us to determine which is fact and which is fiction.