In order to weaken the secular nobility, who threatened his power, Otto endowed Bruno and his successors on the bishop's see with the prerogatives of secular princes, thus establishing the Electorate of Cologne, formed by the temporal possessions of the archbishopric and included in the end a strip of territory along the left Bank of the Rhine east of Jülich, as well as the Duchy of Westphalia on the other side of the Rhine, beyond Berg and Mark.
Prior to World War II the city had undergone several occupations by the French and also by the British (1918–1926).
Cologne was one of the most heavily bombed cities in Germany during World War II, with the Royal Air Force (RAF) dropping 34,711 long tons (35,268 tonnes) of bombs on the city.
Archbishop Sigfried II von Westerburg was forced into exile in Bonn.
The archbishop nevertheless preserved the right of capital punishment.
) is the largest city in the German federal State of North Rhine-Westphalia and the fourth most populated city in Germany (after Berlin, Hamburg, and Munich).