 13.1, places him in 508 BC

On 6 March 12 BC, Augustus became Pontifex Maximus, following the death of Lepidus.Thereafter, it became customary for the emperor to hold the post.Constantine (reigned 306–337) is known as the first emperor to convert to Christianity, but Gratian (375–383) is recorded as the first emperor to decline the office of Pontifex Maximus of the traditional state religion.