On March 15, 44B.C. Julius Caesar, the "dictator for life" of the Roman Empire, was murdered by his own senators at a meeting in a hall next to Pompey's Theatre. The conspiracy against Caesar encompassed as many as sixty noblemen, including Caesar's own protege, Marcus Brutus.
Caesar was scheduled to leave Rome to fight in a war on March 18 and had appointed loyal members of his army to rule the Empire in his absence. The Republican senators, already chafing at having to abide by Caesar's decrees, were particularly angry about the prospect of taking orders from Caesar's underlings. Cassius Longinus started the plot against the dictator, quickly getting his brother-in-law Marcus Brutus to join.