T. J. Andrews & Simon Scarrow 
Arena: Barbarian (Part One of the Roman Arena Series) [EPUB ebook] 

The first in a series of action-packed novellas set in Ancient Rome introducing Pavo, a novice gladiator, and featuring Simon Scarrow’s ongoing soldier character Optio Macro.It is AD 41. The savage Gaul Britomaris has defeated the best of the Roman gladiators in the arena. Now a young volunteer, Marcus Valerius Pavo, the son of a murdered general, has been given a month to prepare to face Britomaris in a fight which only one man can survive. He is to be trained by veteran soldier Macro, who fears for his young trainee’s chances. But Pavo is motivated by more than a simple desire for victory or survival, and Britomaris may yet be facing his most dangerous opponent…