The Ides of March, made famous in the phrase "Beware the Ides of March" was the date of Julius Caesar's death; he was stabbed by Roman senators. The Roman calendar placed the Ides of March on March 15; it was the day on which two new Roman consuls took power.
Prior to his appointment as dictator for life, Caesar added 10 days to the Roman calendar and created a leap year system. His political opponents felt he had too much power and stabbed him 23 times on March 15, 44 B.C. He died at the foot of a statue of Pompey while on his way to a Senate meeting.
The first reference to the Ides of March being associated with Caesar's assassination occurred in Cicero's "Letters to Atticus," which were dated April 19, 44 B.C.
William Shakespeare took this real life event and dramatized it in a passage of his play "Julius Caesar." In the passage, a soothsayer warns Caesar to "Beware the Ides of March."
Rome traditionally held a festival on the Ides of March in honor of Roman deity Anna Perenna. Revelers enjoyed food, wine and music and made sacrifices in an effort to ensure a prosperous new year.