What genre is this novel?

I would call it fantasy. It's not historical in any way, it is merely a modern adaptation of historical events. An example of a historical novel would be any of Bernard Cornwell's 'Richard Sharpe' series that took place before and during the Napoleonic wars.

It sounds like a reimaging. there are many books that do this, like Pride and Prejudice has many modern updates, for example. Now, i'd focus on what the book is about. It doesn't sound fantasy, unless you have fantasy elements. It could just be an commercial novel that's reimaged or based on historical events. You can always say taht it's based on historical events and people. If you get close teh correct genre, then you'll be fine. Sometimes genres can overlap, and it might not evven be genre, it could be commercial fiction. I see thriller in the long list of genres (please don't list all those genres to an agent, and action isn't really a genre). It definitly doesn't sound historical since it's not set in historic times. See what some books that are similar to it are classified as. Ignore the fact that it's based on historical events and people and see if taht helps you get closer to the genre. You don't really say what teh book is about as far as plot goes. I'm not seeing any fantastical or sci-fi elements. No elements of horror. Perhaphs its a thriller (if ti's follows what's expected of that type of genre), and in taht case you'd sub to an agent who represents those types of novels and include the fact taht it's a thriller taht's based on historical events and people. And, since it's based on this war, I woudln't say taht its a reimaging. just say it exactly like you've said it: A thriller that's based on a modern version of the second punic wars. IF it's a thriller, i don't know. Try to get the overall genre correct and you'll be in good hands. If you're not sure if an agent will represent it, sub to the agent anyway, because the least they could do is reject you, and then you keep on keeping on.