In 866 Pope Nicholas I declared that no archbishop might be enthroned or might consecrate the Eucharist till he should receive the _pallium_ at the hands of the Pope.[41] II. _The Mappula._—We have seen in discussing the _alba_ that Pope Sylvester, in the middle of the third century, decreed that the deacons of the city of Rome should substitute _dalmaticae_ for _colobia_; he further charged them to wear a _pallium linostimum_ on their hands. It is clear that this cloth, as its proper name, _mappula_ (little napkin), demonstrates, was designed to serve the utilitarian purpose of a handkerchief, either to wipe the Communion vessels or the face of the minister—probably the latter.[42] This cloth, however, must early have become regarded as a sacred vestment by its wearers, and the exclusive privilege of the Roman priests to wear it was jealously guarded. Attempts were made by the deacons of the neighbouring churches of Ravenna to assume the vestment, and St Gregory found it necessary to interfere, which he did in several letters to that somewhat recalcitrant prelate, John, the Bishop of Ravenna. For the sake of peace, Gregory admitted a compromise whereby the principal deacons of Ravenna were allowed to wear the coveted ornament; but the glamour of carrying a vestment, however inconvenient,[43] which was theoretically confined to the holy city itself, proved too strong a temptation for the deacons of other places, while the Romans (whose exclusive privilege was gone once Ravenna was admitted to a share in it) took no further steps to prevent its assumption. As a natural consequence, the use of the vestment spread over the whole of the Western Church, and by the time when the period at present engaging our attention ended, had become universal.