The Belly of the Bow — K.J. Parker

In one night of blood and betrayal, the famed Triple City of Perimadeia has fallen to the barbarian hordes. The man who led the defending forces, Bardas Loredan, has fled to the island of Scona. Here, eschewing the violence that has characterised his life, he quietly establishes himself as a craftsman, fashioning bows.

Scona is also home to Bardas' brother and sister, the Loredan siblings do not share happy childhood memories. Before long, Bardas is thrown once more into a world of ruthless scheming and bloody rivalries. But it seems to be a world in which Bardas excels, and what he has learnt about the nature of bows is about to change his life -- and the life of his family -- for ever.