Nicaea I, canon 4: provincial ordination
The council's fourth canon calls for a bishop to be appointed by the bishops of the province, or at least three with written consent from absent bishops, subject to metropolitan confirmation. It shows public, collegial episcopal order in the fourth century.
Primary sources
Canon 4 states:
Nicaea's fourth canon begins by requiring provincial bishops to participate in appointing a bishop.
It is by all means proper that a bishop should be appointed by all the bishops in the province
Passage context and translation
Canon 4 continues with provision for at least three bishops to meet when all cannot and requires written consent from absent bishops and metropolitan ratification.
Before the excerpt
Canon 4
After the excerpt
but should this be difficult, either on account of urgent necessity or because of distance, three at least should meet together