Hannibal is remembered as one of the most innovative and dynamic military leaders in world history. He amazingly developed a plan to mount a surprise attack on Rome during the winter. Assembling a large army in Spain, he marched across southern France and into the Italian Alps in the dead of winter. Although losing over 1/2 of his army he still entered the Po valley with a large army of 25,000 troops. His army had an intimidating had a detachment of armored elephants which is unique in European military history. Hannibal's attack surprised the Roman army and he easily defeated them in several battles. Rome, led by the general Fabian, made a decision to hide behind its walled cities (Fabian tactic) and leave the countryside to Hannibal. Rome finally decided to confront Hannibal head-on and met him at the Battle of Cannae in 216 BC. This battle was the most lop-sided in military history with Rome losing over 40,000 troops in a single morning. Rome again retreated behind its walled cities and Hannibal continued to have free reign over the country-side although a lack of supplies kept him defeating the Roman army. Rome finally decided to take the war directly to Carthage and led by a young general, Scipio Africanus, they defeated Hannibal in the Battle of Zama in 201 BC. Carthage lost all of its colonies and retained only the city-state itself.