Caesar n. : A Roman emperor, as being the successor of Augustus Caesar. Hence, a kaiser, or emperor of Germany, or any emperor or powerful ruler. See Kaiser, Kesar.

Example:
Who is the protagonist of the play Julius Caesar?

Taxonomy
Caesar, Suetonius, Plutarch, Julius, Julius Caesar, Pompey, Rome, Gaius Julius Caesar, consul, Dictator, Cassius Dio, the Roman Republic, Roman, Octavian, Gaul, 44 BC, campaign, office.

Defination from the web:
Caesar, the Roman military and political leader. Covers his early life, the Gallic war, his political career and his famous assassination. Also includes depictions of Caesar in art and literature.