“Crossing the Rubicon” is now an expression for passing the point of no return: this is the original incident from which it derives. In 49 BCE, Gaius Julius, at that time just a general and not yet Caesar, led his army across the Rubicon river, which marked the border of Rome: to cross it marked him as a treasonous leader of a revolt against the Roman state. Famously, he is said to have quoted the Greek playwright Menander, saying “alea iacta est” – “the die is cast.”
Julius would be successful in his quest for the leadership of Rome and its empire (much of which, particularly Gaul, added by his own military genius): which is why history knows him best as Julius Caesar.
The ancient feast of the god Lupercus, Lupercalia was an annual three day festival that ran from February 13 – 15 each year. It was intended to avert evil spirits and purify the city, releasing health and fertility. It is the ancient predecessor of the Christian festival of St Valentine, which is now better known as the more secular Valentine’s Day.
According to Shakespeare, when Julius Caesar attended this particular one, he was offered the crown of a monarch three times and refused it on each of those times. Nonetheless, the reason why he was stabbed to death a month later was apparently his limitless ambition.
Shakespeare’s version might be better known, but the best historical account of the death of Big Julie was written by imperial biographer (and obsequious toady) Seutonius. It is from Suetonius that we have Caesar’s famous last words (asking Brutus ‘even you, my child?’, which Shakespeare rendered as ‘et tu, Brute?’) – although curiously, Seutonius himself reports those words as claimed by others, and for himself believes that Caesar said nothing.
This is somewhat hard to believe, given that Seutonius also recounts that Caesar was attacked by 60 or more men, and received a total of 23 stab wounds from his assailants – it appears that the proximate cause of death was loss of blood. (Fun fact: Caesar’s autopsy report is the earliest one to have survived to the present day.) In a larger sense, the cause of the death of Gaius Julius Caesar was political ambition – his own, and that of others.