1. Julius Caesar Crosses the Rubicon
In January 49 B.C., Julius Caesar’s decision to lead his army across the Rubicon River marked a pivotal moment in Roman history. This act directly violated Roman law, which prohibited generals from bringing troops into Italy, and signified his intent to challenge the authority of the Senate. The phrase “crossing the Rubicon” has since become synonymous with making an irreversible decision. (history.com)
