In the first half of the 14th century, Aachen’s citizenry built the city hall under the leadership of its acting mayor Gerhard Chorus (1285–1367) as a sign of their civic freedom. Yet, they had to promise to establish a space in the new town hall that could host the traditional coronation feast that was part of the coronation ceremony of the Holy Roman Empire. Up to then, the nearby mid-13th century Grashaus – which is one of the city’s oldest still-standing buildings – had served the community in that function. Construction began in 1330 on top of the foundation walls of the Aula Regia, part of the derelict Palace of Aachen, built during the Carolingian dynasty. Dating from the time of Charlemagne, the Granus Tower and masonry from that era were incorporated into the south side of the building. The structure was completed in 1349, and while the town hall served as the administrative center of the city, part of the city’s munitions and weaponry was housed in the Granus Tower, which also served as a prison for some time.
From 1380, the entrance of the Kaisertreppe ("Emperor's stairs"), which connected the subterranean levels to the Coronation Hall, was adorned by the limestone relief of the Three Kings and a depiction of the Adoration of the Magi. Four limestone blocks formed the relief, with one serving for each king, and the last depicting Mary and Jesus.
In 1798, during the French period, the relief was partially destroyed, and the remaining pieces were left as they were above the entrance to the main guard station. The medieval artwork was then replaced by Gottfried Götting with a replica in 1879. Before World War II, it was transferred to the local museum (Heimatmuseum) in Aachen and disappeared in the war.
During the great Fire of Aachen in 1656, portions of the roof and towers burned. The destroyed elements were then replaced in a baroque style. From 1727 until 1732 the Chief Architect of Aachen, Johann Joseph Couven, led a fundamental baroque remodeling of the structure, especially of the front façade and entry steps. The gothic figures and muntin adorning the windows were removed, and even the interior was remodeled in the baroque style. Today, the sitting room and the “White Hall” both still convey this change in style.
Characteristic of the time period, the wood paneling of the White Hall is in the style of Aachen-Liège baroque master Jacques de Reux, while the wall painting comes from master painter Johann Chrysant Bollenrath. This hall was originally for a panel of jurists who controlled the quality of cloth produced in Aachen, but the space would later serve as the main office for the mayor of Aachen.
At the treaty signing ceremony that ended the War of Austrian Succession in 1748, the “Peace Hall” was set up but was not used because of a dispute between the envoys. As a compensation for this, the city obtained portraits of the envoys, which can now be found hanging in the various spaces of the City Hall.
Since the end of the Imperial City era and the Napoleonic occupation of the area, the structural condition of the City Hall was greatly neglected, so that the building was seen to be falling apart by 1840. After that, and especially under the watchful eye of 19th century Chief Architect Friedrich Joseph Ark, the building was rebuilt little by little in a neogothic style that tried to capture its original gothic elements. The side of the City Hall that faced the Market was adorned with statues of 50 kings, as well as symbols of art, science, and Christianity.
In the meantime, the Coronation Hall was restored and a new entrance was constructed. In addition, the painter Alfred Rethel had the task to embellish the room with a large series of frescoes. Begun in 1847 and completed by his student in 1861, the frescoes eventually depicted legends from the life of Charlemagne. After the destruction of similar artwork at the Neues Museum in Berlin, this painting is one of the most important testimonies to the late romantic style in Germany.
Starting from a fire in the Johann Peter Joseph Monheim Drug and Material Warehouse at 26 Antonius Street (Antoniusstraße), flames first spread when cinder from the roof landed on the Granus Tower and set it ablaze. Within four hours the roof and both towers of the City Hall were aflame, as were a large number of surrounding houses on the south side of the Market. Within City Hall, the Coronation Hall with its frescoes by Alfred Rethel, as well as the building's first floor, was spared. In the time immediately following the fire, its roof and towers were kept erect through makeshift structures of support.
On 1 November 1884 the city of Aachen initiated a contest among German architects to see who would rebuild City Hall. Of the 13 submitted designs, the first prize went to Aachen architect Georg Frentzen, who in 1891 was commissioned to rebuild the building and its towers. The restoration of the inner rooms was performed under the leadership of Joseph Laurent, and around 1895 sculptures depicting the Knight Gerhard Chorus and Johann von Punt (who was leader of the city six times from 1372 to 1385) were reinstalled in the bay windows on the back side of City Hall, and the eight shields depicting the coat of arms of medieval nobility (Margarten, Berensberg, Roide, Hasselholz, Surse, Wilde, Joh Chorus, and Zevel) were remade in the spandrels. This was done by Karl Krauß.
The restoration was finally finished in 1902, and the unveiling of the Rathaus took place with the blessing of Kaiser Wilhelm II, Emperor of Germany, on 19 June 1902.
Aachen’s city hall survived World War I without sustaining damage, but during civil unrest that arose in the course of a separatists’ movement whose goal was the creation of an independent Rhenish Republic, City Hall was stormed by a group of separatists who caused serious damage both to its interior and exterior. Parts of the façade, such as adorning statues and both clocks, were broken, as were all window panes on the first floor on the Market side. Additionally, several rooms inside the building were ransacked, and many of the famed frescoes within were heavily damaged by gunfire. The furniture (especially that within the mayoral office and Coronation Hall) were damaged as they were used as projectiles. In the Emperor Hall, an undetonated bomb was discovered.
During World War II, Aachen City Hall was heavily damaged by bombing raids, especially those occurring on 14 July 1943 and 11 April 1944. On 14 July 1943 the roof of the building and both towers burned, and afterwards the structure retained a distinctive shape due to the heat that twisted the steel skeletons inside the tower caps. The Coronation Hall was again heavily damaged and the north facing wall was moved in places up to 30 centimeters vertically. The imminent threat of collapse was staved off through the use of emergency beams that held the structure in place. Because of rain penetrating the interior of the building, its frescoes were severely affected, and five of the eight were carefully removed by Franz Stiewi and stored at the Suermondt-Ludwig-Museum.
The architect Professor Otto Gruber and the building engineer Professor Richard Stumpf prepared a report in 1945 about the structural integrity of the building. With the help of Professor Josef Pirlet, the dilapidated north façade was reinforced with steel and tension bars, and in 1946, the building’s roof was repaired using makeshift sheets of zinc. After structural analysis was conducted and the foreground was reinforced, the replacement of the north façade had to take place, since almost all of the arches there were broken. The arches on the ground floor were again closed for repairs in 1950, and the reconstruction of the Emperor Hall was largely completed by 1953, with the configuration of the room following in the next few years.
The question of how the tower caps should be rebuilt remained at the heart of a controversial discussion. In 1966 Professor Wilhelm K. Fischer, who had worked extensively in the reconstruction of Aachen, produced a sketch for the towers’ design, as students from RWTH Aachen University also took part in the debate, submitted 24 designs for consideration. In 1968 eight additional expert designs were submitted to a working group whose task it was to rebuild the towers, and after discussing several modern looks, the group settled on a design by the conservation-restoration expert Leo Hugot, who stuck tightly to the historical image of the towers. The tower caps were finally finished in 1978.
Today, replicas of the Imperial Regalia from the Viennese Imperial Treasury reside in the city hall. These replicas were made around 1915 by order of Emperor Wilhelm II for an exhibition to recall the 31 coronations that took place in Aachen between 813 and 1531. Among the replicas are a copy of the Vienna Coronation Gospels, the Sabre of Charlemagne, the Imperial Crown of Otto I, and the Imperial Orb.
Since 2009, Aachen City Hall has been a station on the Route Charlemagne, a tour program by which historical sights of Aachen are presented to visitors. At the city hall, a museum exhibition explains the history and art of the building and gives a sense of the historical coronation banquets that took place there. A portrait of Napoleon from 1807 by Louis-André-Gabriel Bouchet and one of his wife Joséphine from 1805 by Robert Lefèvre are viewable as part of the tour.
As before, the city hall is the seat of the mayor of Aachen and of the city council, and annually the Charlemagne Prize is awarded there.