Gaius Julius Caesar[1] (pronounced [ˈɡaː.i.us ˈjuːli.us ˈkaɪsar] in Classical Latin; conventionally /ˈɡaɪ.əs ˈdʒuːli.əs ˈsiːzər/ in English), (13 July 100 BC[2] – 15 March 44 BC),[3] was a Roman military and political leader. He played a critical role in the transformation of the Roman Republic into the Roman Empire.