Et tu, Brute? (pronounced [?t ?tu? ?bru?t?]) is a Latin phrase meaning “and you, Brutus?” It is notable for its occurrence in William Shakespeare’s play Julius Caesar, where it is spoken by the Roman dictator Julius Caesar to his friend Marcus Junius Brutus at the moment of Caesar’s assassination. The phrase’s first known occurrences are said to be in two Elizabethan plays: an early play by Shakespeare, and an even earlier play that is now lost.[1] The phrase is often used apart from the plays to signify an unexpected betrayal by a friend.
Caesar utters these words in Act III, scene 1, as he is being stabbed to death, having recognized his friend and protégé Brutus as one of the assassins. There is however no evidence that the historic Caesar spoke these words.[2][