Hannibal, Enemy of Rome, Ben Kane.
It starts just before the 2nd Punic War and ends with the Battle of Trebia. It is the first volume of a trilogy.
The main characters are three teenagers, Hanno (from Carthage) and Quintus and Aurelia (Roman citizens without the franchise from Capua).
The novel describes how the three become friends and how that friendship is tested in the face of war between their two cities.
There is a ...