 Bishops had no part in the civil administration until the town councils, in decline, lost much authority to a group of 'notables' made up of the richest councilors, powerful and rich persons legally exempted from serving on the councils, retired military, and bishops post-450 AD.As the Western Empire collapsed in the 5th century, bishops in Western Europe assumed a larger part of the role of the former Roman governors.A similar, though less pronounced, development occurred in the East, where the Roman administrative apparatus was largely retained by the Byzantine Empire.