You're partially right there. History is, by it's nature, biased. Whether you're talking about Roman, Serbian, or American history, each person is going to bring a certain viewpoint to the table. That viewpoint is going to depend on where the person was educated, and what type of experience they've had in the world.
However, historical events happen. Julius Caesar conquered Gaul. Archduke Ferdinand was assassinated. Abraham Lincoln was President during the Civil War. These events happened, regardless of political bias.
What becomes a dangerous topic on our Boards is when people start offering their own opinions onto these events, e.g. "Julius Caesar conquered Gaul and I think that was right." Now, you are no longer discussing a historical event. Instead, you are giving political discussion on a topic.