What were Julius Caesars last words?

Answer 1

Historically they are in dispute, though they are frequently claimed to be "Kai su, teknon?" This phrase is Greek, translated as either "even you child" or a Greek curse approximating a stronger version of "Damn you, boy!" Both Suetonius and Plutarch (two preeminent ancient historians) claimed silence, though Suetonius wrote about the possibility of the statement "Kai su, teknon?"

In the Shakespearean play they are:

"Et tu, Brute? Then fall, Caesar!"

Caesar said "Et tu Brute" (even you Brutus!) as he was surprised that Brutus had joined into the assassination plot.

Answer 2

According to the accounts at the time Caesar said nothing as he died. The famous phrase "Et tu, Brute?" was first heard in William Shakespeare's play, and has no credible historic grounding.