It was vowed by Octavian in return for the victory over Sextus Pompeius at the Battle of Naulochus in 36 BC and over Mark Antony and Cleopatra at the Battle of Actium 31 BC, and was built on a site where a lightning bolt had struck the interior of Augustus' property on the Palatine. It was dedicated on October 9, 28 BC. The ludi saeculares, reinstituted by Augustus in 17 BC and also largely developed and funded by him, involved the new temple.