History isn't what happened, but a story of what happened. And there are always different versions, different stories, about the same events. One version might revolve mainly around a specific set of facts while another version might minimize them or not include them at all.
      Like stories, each of these different versions of history contain different lessons. Some histories tell us that our leaders, at least, have always tried to do right for everyone. Others remark that the emperors don't have the slaves' best interests at heart. Some teach us that this is both what has always been and what always will be. Others counsel that we shouldn't mistake transient dominance for intrinsic superiority. Lastly, some histories paint a picture where only the elites have the power to change the world, while others point out that social change is rarely commanded from the top down.

       Regardless of the value of these many lessons, History isn't what happened, but the stories of what happened and the lessons these stories include. The very selection of which histories to teach in a society shapes our view of how what is came to be and, in turn, what we understand as possible. This choice of which history to teach can never be "neutral" or "objective." Those who choose, either following a set agenda or guided by hidden prejudices, serve their interests. Their interests could be to continue this world as it now stands or to make a new world. 
      We cannot simply be passive. We must choose whose interests are best: those who want to keep things going as they are or those who want to work to make a better world. If we choose the latter, we must seek out the tools we will need. History is just one tool to shape our understanding of our world. And every tool is a weapon if you hold it right.