Roman Catholic Diocese of Aachen

The Diocese of Aachen (Dioecesis Aquisgranensis) is a Latin diocese of the Catholic Church located in Germany and one of the six dioceses in the ecclesiastical province of Cologne. The incumbent bishop is Helmut Dieser, who was appointed by Pope Francis on 23 September 2016. The bishop's seat is Aachen.

Geography
The diocese is located in the very west of Germany, extending from Krefeld in the north to the mountainous Eifel area in the south. Bordering dioceses are Cologne, Münster, Essen and Trier in Germany, Liège in Belgium and Roermond in the Netherlands.

The diocese is divided into seven regions which are in turn further subdivided into 538 parishesː
 * 1) Region Aachen-Stadt (Aachen city)
 * 2) Region Düren
 * 3) Region Eifel
 * 4) Region Heinsberg
 * 5) Region Kempen Viersen
 * 6) Region Krefeld
 * 7) Region Mönchengladbach

Ordinaries
The bishop emeritus of Aachen is Heinrich Mussinghoff. There are two auxiliary bishops, Johannes Bündgens and Karl Borsch. Also, there are two emeritus auxiliary bishops, Gerd Dicke and Karl Reger. The vicar general is Andreas Frick.

History
Historically, today's territory of the Diocese of Aachen belonged to the Diocese of Liège and the Archdiocese of Cologne. The diocese was first created in 1802, covering the area west of the Rhine formerly belonging to Cologne, as well as parts from the dioceses Liège, Utrecht, Roermond and Mainz. After the first bishop Marc Antoine Berdolet died in 1809, Pope Pius VII refused to commission the successor suggested by Napoleon, Jean Denis François Camus. After the French rulership over the area, the diocese was abolished by the bull De salute animarum of July 16, 1821, and incorporated into the archdiocese of Cologne.

On August 13, 1930 the diocese was re-established by the papal bull Pastorale officii nostri. Joseph Vogt was appointed as its first bishop.

Major Churches
The principal church of the diocese is the Aachen Cathedral, of which the central part, the Palatine Chapel, was built in 800 under Charlemagne. It was also the first German World Heritage Site, inscribed in 1978.

The diocese has two churches that have been given the status of basilica minorː
 * Steinfeld Basilica, Kall-Steinfeld – 7 October 1960
 * Minster St. Vitus, Mönchengladbach – 25 April 1973