The emperor renounced investiture by ring and staff, and permitted canonical elections; the pope on his part recognized the king's right to perform lay investiture and to assist at elections.
In the canonical form f=k1(px)5 +k2(gx) 5 +k3(rx) 5 .
They must therefore have been regarded as canonical in the first half of the 4th century.
In all cases canonical institution (which confers ecclesiastical jurisdiction) is reserved to the pope or the bishops.
Isolated examples in the early middle ages of metropolitans dealing with their suffragan bishops by imprisonment in chains were extra-canonical abuses, connected with the perversion of Church law which treated the metropolitan (who originally was merely convener of the provincial synod and its representative during the intervals of sessions) as the feudal " lord " of his comprovincials.