Hannibal was a Punic Carthaginian military commander, generally considered one of the greatest military commanders in history. His father, Hamilcar Barca, was the leading Carthaginian commander during the First Punic War. His younger brothers were Mago and Hasdrubal, and he was brother-in-law to Hasdrubal the Fair. Hannibal lived during a period of great tension in the Mediterranean, when the Roman Republic established its supremacy over other great powers such as Carthage and the Hellenistic kingdoms of Macedon, Syracuse, and the Seleucid Empire. One of his most famous achievements was at the outbreak of the Second Punic War, when he marched an army, which included elephants, from Iberia over the Pyrenees and the Alps into Italy. In his first few years in Italy, he won three dramatic victories-Trebia, Trasimene, and Cannae, in which he distinguished himself for his ability to determine his and his opponent's strengths and weaknesses, and to play the battle to his strengths and the enemy's weaknesses-and won over many allies of Rome.