War of the Celts / by Jack Whyte.

A country in ruins A struggle for survival A dynasty begun The Empire is collapsing and after 450 years of occupying Britain, the Roman legions are departing to defend the Homeland. Soldier turned blacksmith Publius Varrus and his friend, the Legate Caius Britannicus, decide to stay behind and build a new life in the chaos that is left behind. They dream of rebuilding their Empire, this time free of the corruption that destroyed it, and firmly based on the island of Britain, despite its being bathed in blood and brutalised by tribal invasion. Their dream is a thousand years premature, but the first step towards it is the unification of the country under one man, a monarch whose fame will echo through the ages: Publius' great grandson: Arthur Pendragon, King of the Britons. Discover the most authentic telling of the Arthurian legend ever written