Gaius (Caligula) Caesar.

Fourth of the Caesars.

Period of principate.
37 to 41.

Related and attributed text(s).
Tacitus, Annals 7.10 (related), lost.
Suetonius, Caligula (related), available in Latin and English (LacusCurtius).
Cassius Dio, Roman History (related), available in English (LacusCurtius).

Useful links.
Caligula at Wikipedia.
Caligula at Roman Emperors.

Gaius (Caligula) Caesar was the fourth of the twelve Caesars for whom Suetonius wrote a biography.