Historically the archbishop was ex officio one of the prince-electors of the Holy Roman Empire and ruled the Electorate of Cologne.
Since the early days of the Catholic Church, there have been ninety-four bishops and archbishops of Cologne.
Additionally, six of the archbishops of Cologne were chairmen of the German Bishops' Conference.
All names before Maternus II are to be approached with considerable skepticism, as little contemporary evidence is available.
Domitianus was the Bishop of Maastricht (Mosa Traiectum).