The show focuses on his legendary excesses, including declaring himself a living god, his alleged incestuous relationships with his sisters, and the famous (though historically debated) story of naming his horse, Incitatus, as a consul.

The series follows Caligula (played by Ido Drent) from his traumatic childhood under the paranoid Emperor Tiberius to his own bloody reign. It depicts his initial popularity, his descent into madness following a near-fatal illness, and his eventual assassination by the Praetorian Guard.

: His reign began with hope; he initially reformed the government and treated his family with great honor.