Gaius Julius Caesar (b. July 12, c.100 BC d. March 15, 44 BC) was a Roman military and political leader. He was instrumental in the transformation of the Roman Republic into the Roman Empire. In 55BC Caesar launched the first Roman invasion of Britain, and his conquest of Gallia Comata extended the Roman world all the way to the Atlantic Ocean, introducing Roman influence into what has become modern France, an accomplishment of which direct consequences are visible to this day. Caesar fought and won a civil war which left him undisputed master of the Roman world, and began extensive reforms of Roman society and government. He was proclaimed dictator for life, and heavily centralized the already faltering government of the weak republic. Caesar's friend Marcus Brutus conspired with others to assasinate Caesar in hopes of saving the Republic. The dramatic assassination on the Ides of March was the catalyst for a second set of civil wars, which marked the end of the Roman Republic and the beginning of the Roman Empire under Caesar's grand-nephew and adopted son, Caesar Augustus.