NS Documentation Centre of the City of Cologne NS Documentation Centre of the City of Cologne The NS Documentation Centre of the City of Cologne () was founded by a resolution passed by the Cologne city council on December 13, 1979 and has become the largest regional memorial site in all of Germany for the victims of the Nazis. Since 1988, it has been housed in "EL-DE Haus," the EL-DE building, named for the initials of its owner, Catholic businessman Leopold Dahmen. This building was the headquarters of the Cologne Gestapo (secret police) between December 1935 and March 1945. In the final months of the war, several hundred
Electorate of Cologne confused with the Roman Catholic Archdiocese of Cologne, which was larger and included suffragant bishoprics such as Liège and Münster over which the Elector-Archbishop exercised only spiritual authority (see map below). Cologne was the ancient Roman city of Colonia Agrippina in the province of Germania Inferior, and has been a bishop's see since Roman times. In 953, the archbishops of Cologne first gained noteworthy secular power, when Bishop Bruno was appointed as duke by his brother Emperor Otto I. To weaken the secular nobility, who threatened his power, Otto endowed Bruno and his successors in the bishop's see with the