It is the westernmost larger city in Germany, lying approximately 61 km (38 mi) west of Cologne and Bonn, directly bordering Belgium in the southwest, and the Netherlands in the northwest.

The once Celtic settlement was equipped with several thermae in the course of colonization by Roman pioneers settling at the warm Aachen thermal springs around the 1st century.

[6][7] This word became Åxhe in Walloon and Aix in French, and subsequently Aix-la-Chapelle to distinguish it from Aix-en-Provence, after Charlemagne had his palatine chapel built there in the late 8th century and then made the city his empire's capital.

During the Iron Age, the area was settled by Celtic peoples[11] who were perhaps drawn by the marshy Aachen basin's hot sulphur springs where they worshipped Grannus, god of light and healing.

Roman civil administration in Aachen eventually broke down as the baths and other public buildings (along with most of the villae rusticae of the surrounding countryside) were destroyed around AD 375 at the start of the migration period.

[20] After Charlemagne's death, he was buried in the church which he had built;[21] his original tomb has been lost, while his alleged remains are preserved in the Karlsschrein, the shrine where he was reburied after being declared a saint; his saintliness, however, was never officially acknowledged by the Roman Curia as such.

[12][25] During the Middle Ages, Aachen remained a city of regional importance, due to its proximity to Flanders; it achieved a modest position in the trade in woollen cloths, favoured by imperial privilege.

As an imperial city, Aachen held certain political privileges that allowed it to remain independent[clarification needed] of the troubles of Europe for many years.

The main indication for visiting patients, ironically, was syphilis; only by the end of the 19th century had rheumatism become the most important object of cures at Aachen and Burtscheid.

As recently as the late 18th century the Abbess of Burtscheid was still prevented from building a road linking her territory to the neighbouring estates of the duke of Jülich; the city of Aachen deployed its handful of soldiers to chase away road-diggers.

[citation needed] On 9 February 1801, the Peace of Lunéville removed the ownership of Aachen and the entire "left bank" of the Rhine from Germany (the Holy Roman Empire) and granted it to France.

[44] With reinforcements from the US 28th Infantry Division[45] the battle continued involving direct assaults through the heavily defended city, which forced the German garrison to surrender on 21 October 1944.

As the westernmost city in Germany[6] (and close to the Low Countries), Aachen and the surrounding area belongs to a temperate climate zone (Cfb), with humid weather, mild winters, and warm summers.

Because of its location north of the Eifel and the High Fens and its subsequent prevailing westerly weather patterns, rainfall in Aachen (on average 805 mm/year) is comparatively higher than, for example, in Bonn (with 669 mm/year).

Another factor in the local weather forces of Aachen is the occurrence of Foehn winds on the southerly air currents, which results from the city's geographic location on the northern edge of the Eifel.

The city's numerous cold air corridors, which are slated to remain as free as possible from new construction, therefore play an important role in the urban climate of Aachen.

The city's oceanic climate provides comparably mild winters: While Aachen falls within the coldest extents covered by USDA plant hardiness zone 8b in the 1991–2020 period, having an average yearly minimum of -9.22 °C (15.4 °F), the Canadian city of Regina, Saskatchewan which is located at a similar latitude but at the heart of the North American landmass, far away from the sea's moderating effects, is classified as being in zone 3a.

The oldest occurring rocks in the area surrounding the city originate from the Devonian period and include carboniferous sandstone, greywacke, claystone and limestone.

[56] During the Cretaceous period, the ocean penetrated the continent from the direction of the North Sea up to the mountainous area near Aachen, bringing with it clay, sand, and chalk deposits.

More recent sedimentation is mainly located in the north and east of Aachen and was formed through tertiary and quaternary river and wind activities.

[68] Most of the marble and columns used in the construction of the cathedral were brought from Rome and Ravenna, including the sarcophagus in which Charlemagne was eventually laid to rest.

The Coronation Gospels and a reliquary burse of St. Stephen were moved to Vienna in 1798 and the Talisman of Charlemagne was given as a gift in 1804 to Josephine Bonaparte and subsequently to Rheims Cathedral.

There are numerous other notable churches and monasteries, a few remarkable 17th- and 18th-century buildings in the particular Baroque style typical of the region, a synagogue, a collection of statues and monuments, park areas, cemeteries, among others.

[25] Though once a major player in Aachen's economy, today glassware and textile production make up only 10% of total manufacturing jobs in the city.

In June 2010, Achim Kampker, together with Günther Schuh, founded a small company to develop electric powered light utility vehicles; in August 2014, it was renamed StreetScooter GmbH.

[74] At the time, this target would make it the largest electric light utility vehicle manufacturer in Europe, surpassing Renault's smaller Kangoo Z.E.

[83] The annual CHIO (short for the French term Concours Hippique International Officiel) is the biggest equestrian meeting of the world and among horsemen is considered to be as prestigious for equitation as the tournament of Wimbledon for tennis.

Many tram lines extended to the surrounding towns of Herzogenrath, Stolberg, Alsdorf as well as the Belgian and Dutch communes of Vaals, Kelmis (then Altenberg) and Eupen.

Since 1950, a committee of Aachen citizens annually awards the Charlemagne Prize (German: Karlspreis) to personalities of outstanding service to the unification of Europe.

[86] The poem is a first-person narrative told, in breathless galloping meter, by one of three riders; an urgent midnight errand to deliver "the news which alone could save Aix from her fate".