This movie is display about one of the first recorded battles in history, a battle that changes the course of humanity. The displayed story is about the battle of Thermopylae where 300 Spartans face the power of the undefeated Persian army.
To have a better understanding of the movie, you need to understand the historical context. While critics don’t like the movie, they describe it as unreal, represented by superior forces.
But in my opinion I think the purpose of this movie is not to show the historical truth. The goal is to show how people at that time lived with the evens, or how events were told after the glorious fight.
The historical truth about this battle was that Spartans did sent 300 warriors, but they also were joined by many other Helens, so the modern historians say that there were around 20,000 Helens, against 150,000 Persians.
The only way to enjoy this movie is to have those things in mind. For some, this movie will bring disappointment after they see what will happen in the movie. However, some will be fascinated by how people imagined those events, because in that view, there are no mistakes in this movie.
[Source](http://cdn.collider.com/wp-content/uploads/300-rise-of-an-empire-sullivan-stapleton1.jpg)