Roman history is not my favorite, but this is a story of the "limes", the border, and the story of the end of the Roman Empire.
First of all, the main character is a tired man, an old man, and tells us the story in first person. We can't avoid the fact that he is no more than a soldier, and talks and acts like a soldier. He is a men of few words, and obeys orders.
The best, the story about the final battle. The worst, the characters are not very well defined. But enjoyed it, and it paints us a good fresco from the decadent empire.