The Last Roman (The Praetorian Series - Book I) by Edward Crichton
Series: The Praetorian, I.
Approx. 146,010 words.
Published on June 26, 2012.
When Navy SEAL Jacob Hunter is sent to Syria on a mission to eliminate a terrorist cell, his team discovers a mysterious artifact instead. Later, in the furor of battle, its ancient power is activated and the team is hurled through time & space to the age of Ancient Rome, where their first priority is to find a way home. But Rome's duplicitous elite have other plans for these powerful newcomers...