Alea iacta est

Alea iacta est ("The die is cast") is a variation of a Latin phrase (iacta alea est [ˈjakta ˈaːlɛ.a ˈɛs̺t]) attributed by Suetonius to Julius Caesar on 10 January 49 BC, as he led his army across the Rubicon river in Northern Italy, in defiance of the Roman Senate and beginning a long civil war against Pompey and the Optimates. The phrase is often used to indicate events that have passed a point of no return.

The phrase was a quote from a play by Menander, and according to Plutarch, Caesar originally said the line in Greek rather than Latin. The Latin version is now most commonly cited with the word order changed (Alea iacta est), and it is used both in this form, and in translation in many languages. The same event inspired another related idiom, "crossing the Rubicon".