The Early Church
In the earliest days bishops preserved the Unity with the Universal Church through gathering in episcopal synods there they adresses questions of concern. It was important for the local Churches to stay connected to the Universal Church. This showed that the Bishops of Local Churches had responsibility for the Universal Church.
Second Vatican Council
The second Vatican Council emphasizes the cushions role as a teacher and a pastor confirmed through Holy Orders. The Collage of a Bishops preserves the unity of the Universal Church. The Doctorine of Episcopal collegiality states that the whole collage shares authority over the Universal Church. Bishops only have authority with the Pope.