Tyrant by Christian Cameron
A well-born officer of Athenian cavalry, Kineas fought shoulder to shoulder with Alexander in his epic battles against the Persian hordes. But when he returns to his native city, he finds not glory but ignominy, as all veterans of the Boy King's campaigns are sent into exile. With nothing to his name but his military skills, Kineas has no choice but to become a mercenary, and soon accepts a commission to soldier for the Tyrant of Olbia, a wealthy city on the Black Sea. But when he reaches Olbia he finds he and his tight-knit band of Athenians have stumbled into a deadly maze of intrigue and conspiracy as the Tyrant plots to use them as a pawn in the increasingly complex power games between his own citizens, the so-called barbarians of the encroaching Scythian plains, and the dread military might of Macedon. Caught between his duty to the Tyrant, his loyalty to his men and a forbidden love affair with a charismatic Scythian noblewoman, Kineas must call on all his Athenian guile, his flair on the battlefield, and even - he is convinced - the intervention of the gods, to survive.