In ancient Rome, the Ides were a mid-month festival. The Ides of March often featured a military procession dedicated to Mars, the god of war.
Every good Latin scholar should be aware that "In March, July, October, May, the Ides fall on the 15th day". In other months, the Ides are on the 13th.
After being warned to "beware the Idea of March" Julius Caesar was stabbed to death by a group of conspirators on the Ides of March in 44BC. He died from the second of 23 stab wounds, according to a physician who examined the body and provided the earliest known post-mortem report. Between them, the cast of the George Clooney film The Ides Of March had 23 Golden Globe nominations when the film was released, one for each stab wound of Julius Caesar.
The Ides of March is the earliest day on which Palm Sunday can fall. March 15 is also World Consumer Rights Day and the International Day Against Police Brutality.
The Ides of March is also the only date in the calendar on which a serving US President and British prime minister shared a birthday: from 1835-1837, the UK prime minister (Lord Melbourne) and US president (Andrew Jackson) both celebrated 15 March birthdays.