The Silver Branch
The Silver Branch by Rosemary Sutcliff
Rating 10 +
Recommended Reading Age: 12
This book (like The Eagle of the Ninth) was a very good story about Britain close to the end of Rome's rule over her.
When the main characters warn the emperor of an internal plot, he acts angrily and sends them away. Later, at the exiled characters new post, they hear that the usurper, Allectus, has succeeded in murdering the emperor and acceding the throne. For the rest of this story, they work to bring together a band to fight Allectus, seek revenge for the old emperor's life and save the future of Britain.
I would recommend reading this after reading The Eagle of the Ninth, because there are points in this book that, for people who have read the before mentioned, will bring many "Oh, wow, I remember that" moments.