14. Julius Caesar
By crossing the Rubicon in 49 B.C., Julius Caesar demonstrated supreme self-assurance, defying the Roman Senate’s orders and initiating a civil war. This bold move led to his consolidation of power and eventual appointment as dictator perpetuo (“dictator in perpetuity”) in early 44 B.C. His disregard for traditional republican governance and accumulation of power shocked Rome, culminating in his assassination on the Ides of March, 44 B.C., by a group of senators who feared his monarchical ambitions (en.wikipedia.org).
