As Roman Diakonia one called special buildings in the seven historic church regiones (district ), in which the early Christian Rome was divided.

The division of Rome in regiones leaned on to the administrative division of the Roman city administration. The task of diakonia was to care for the poor of the respective district. In each of these quarters was erected a building ( diaconia ) - usually in the immediate vicinity of a Roman church - which served the inclusion of the poor. The head of such diakonia was called a deacon ( in the course of time Diaconi ecclesiae Romanae ); gradually this head were also Diaconi cardinal (cardinal deacons ) called. This cardinal deacons are now a class of cardinals.