[3] His tenure as bishop in the first quarter of the 6th century fell in the politically troubled times during the expansion of Frankish power into the region around Trier.
His name is given in the Trier bishops' lists and in the Vita Goaris, a hagiography of Saint Goar.
While he was bishop, the revival of the power of the church in Trier was gradually beginning after a period of obscurity and weakness due to the political situation.
This is evidenced by the resumption of earlier attempts at evangelization in areas on the Middle Rhine.
In this context, Fibicius probably gave permission in about 511 to Saint Goar to build a church in Oberwesel.