Hannibal is often considered the finest general the world has ever known. Setting out from Carthaginian-dominated Spain with a small army of select troops, he fought his way over the Pyrenees and crossed the Alps with elephants and a full baggage train. Descending into Italy, he destroyed the main Roman army at Lake Trasimeno and came close to conquering Rome itself. At Cannae, Hannibal's brilliant cavalry tactics enabled him to cut to pieces a reassembled...