FRONTIER WOLF, by Rosemary Sutcliff (Front Street 2008, orig. pub. 1981)(12+). In 343 AD, disgraced centurion Alexios Flavio Aquila is given one last chance to redeem himself and salvage his career. At the intervention of his uncle, he's sent to the wilds of northern Britain to command the "Frontier Wolves," sort of the French Foreign Legion of its day.
He begins to get the feel of leadership on the strange frontier, but when the tribes rise against the Romans, he's faced with the dilemma that cost him his reputation last time: stay and fight or retreat?
FRONTIER WOLF is compelling, richly-detailed, action-packed historical fiction. Flavios is engaging and sympathetic as he struggles with his new command and the conflict between following standing orders and on-the-scene judgment.
Sutcliff is also author of THE EAGLE OF THE NINTH, which was just issued in paperback as THE EAGLE by Square Fish/Macmillan in conjunction with the release of the movie based on the book.