Eustasius of Aosta

His name is attached to a letter sent to Pope Leo I by the delegates of the second Synod of Milan (451).

[1][2] Eustasius is traditionally regarded as the first bishop of the ancient Augusta Pretoria, today Aosta.

[3] Pope Benedict XVI thought he was of Sardinian origin.

[4] According to St Ambrose, the people of Aosta asked Eusebius to have their own bishop some time after 400 AD, and Eustasius was sent to Aosta as the first bishop.

Indeed, for a long time the first bishop of Aosta was not celebrated in the diocese at all, and even today his cult is purely local.