Question

The video you just watched revolved around a poet's interpretation of the moment Julius Caesar chose to cross the Rubicon River. Historically, at that moment Caesar is said to have muttered in Greek, "…let the dice fly!" However, when that moment is referred to by Medieval or Renaissance historians, they almost always use the Latin version rather than the Greek: "Alea Jacta Est." Why?

Answer 1

Alea iacta est ("The die is cast") is a variation of a Latin phrase (iacta alea est)  attributed by Suetonius to Julius Caesar who pronounced it in the year 49 B.C. when he was leading his army across the Rubicon river in the current territories of Northern Italy. Subsequently, he entered in Italy heading his army and defying the Roman Senate and it meant the beginning of the civil war versus Pompey and the Optimates.

• Plutarch, referred to the same event in his written testimonies and reported the phrase but stating it was pronounced in Greek instead of Latin and that its translation meant: 'Let the die be cast'.
• Suetonius described the same situation, reporting a very similar phrase but not exactly the same. Let's include the exact excerpt of his writings where he did so.

Caesar: '... iacta alea est,' inquit.

Caesar said, "The die has been cast."

Thefore there are two very similar versions of the same historical events. Usually the Latin version is the most widely known, as the Latin language was more widespread all over Europe and gave rise to all the current family of Latin languages (Spanish, French, Italian, Portuguese, etc).