Letter XLII. To Ravennius, Bishop of Arles. Leo the Pope to his well-beloved brother Ravennius. He asks him to deal with the imposture of a certain Petronianus. We wish you to be circumspect and careful lest any blameworthy presumption should put forth undue claims:  for, when it once finds an entrance by crafty stealth, it spreads itself into greater rashness in the name of the dignity it has assumed.  We have learnt, on the trustworthy evidence of your clergy, that a certain wandering and vagabond Petronianus has boasted himself throughout the provinces of Gaul as our deacon, and under cover of this office is going about the various churches of that country.  We desire you, beloved brother, so to check his abominable effrontery, as to disclose his imposture, by warning the bishops of the whole district, and to expel him from communion with all the Churches, lest he continue his claim.  The Lord keep you safe, dearly beloved brother.  Dated 26th, August, in the consulship of the illustrious Asturius and Protogenes (449).