Myth: Caligula Slept with His Sisters

Caligula is a prominent subject of character assassination. Indeed, quite probably he was a relatively incompetent ruler and not a very nice human being, but the main problem here is that we have only two primary sources describing his rule: ancient historians Suetonius and Cassius Dio. Both are extremely, horrifyingly biased.

When a historian accuses someone of incest it is basically a headshot in his assassination attempt.