August 31

- pridie Kalendas September
A.D. 12 Birthday of Caligula (aka Caius Caesar Germanicus).
A.D. 40 Caligula returned from his victory over the seashells.
A.D. 161 Emperor Commodus born in Lanuvium.

This Day in History | Daily Quiz | Roman Calendar Terminology | On the Inaccuracy of This Day in Ancient History