Founded in the 1st century BC as a settlement of the Ubii and later part of the Roman province Germania Inferior, Bonn is among Germany's oldest cities.

[3] Following reunification, a political compromise known as the Berlin-Bonn Act ensured that the German federal government retained a significant presence in Bonn.

[7] Birthplace of composer Ludwig van Beethoven, a center of Rhenish carnival, and its geography by the Middle Rhine make it an important tourist destination.

Situated in the southernmost part of the Rhine-Ruhr region, Germany's largest metropolitan area with over 11 million inhabitants, Bonn lies within the German state of North Rhine-Westphalia, on the border with Rhineland-Palatinate.

The Bonn weather station has recorded the following extreme values:[9] The history of the city dates back to Roman times.

In about 12 BC, the Roman army appears to have stationed a small unit in what is presently the historical centre of the city.

Even earlier, the army had resettled members of a Germanic tribal group allied with Rome, the Ubii, in Bonn.

[10] The Eburoni were members of a large tribal coalition effectively wiped out during the final phase of Caesar's War in Gaul.

During the 1st century AD, the army then chose a site to the north of the emerging town in what is now the section of Bonn-Castell to build a large military installation dubbed Castra Bonnensis, i.e., literally, "Fort Bonn".

With additions, changes and new construction, the fort remained in use by the army into the waning days of the Western Roman Empire, possibly the mid-5th century.

Between its walls it contained a dense grid of streets and a multitude of buildings, ranging from spacious headquarters and large officers' quarters to barracks, stables and a military jail.

Units of the Bonn legion were deployed to theatres of war ranging from modern-day Algeria to what is now the Russian republic of Chechnya.

Local legends arose from this period that the name of the village came from Saint Boniface via Vulgar Latin *Bonnifatia, but this proved to be a myth.

The elector Clemens August (ruled 1723–1761) ordered the construction of a series of Baroque buildings which still give the city its character.

In addition he was a patron of the young Ludwig van Beethoven, who was born in Bonn in 1770; the elector financed the composer's first journey to Vienna.

During the Second World War, Bonn acquired military significance because of its strategic location on the Rhine, which formed a natural barrier to easy penetration into the German heartland from the west.

Following the advocacy of West Germany's first chancellor, Konrad Adenauer, a former Cologne Mayor and a native of that area, Bonn became the de facto capital and seat of government, officially designated the "temporary seat of the Federal institutions" of the newly formed Federal Republic of Germany in 1949.

In 1949, the Parliamentary Council in Bonn drafted and adopted the current German constitution, the Basic Law for the Federal Republic of Germany.

It used to be based in the Rococo-style Altes Rathaus (old city hall), built in 1737, located adjacent to Bonn's central market square.

However, due to the enlargement of Bonn in 1969 through the incorporation of Beuel and Bad Godesberg, it moved into the larger Stadthaus facilities further north.

As Dörner was elected Lord Mayor of Bonn in September 2020, she resigned as a member of parliament after her entry into office.

Next to the market place is the Old City Hall, built in 1737 in Rococo style, under the rule of Clemens August of Bavaria.

[22] German artists on display include Georg Baselitz, Joseph Beuys, Hanne Darboven, Anselm Kiefer, Blinky Palermo and Wolf Vostell.

Affiliated with the University of Bonn, it is also a zoological research institution housing the Leibniz-Institut für Biodiversität der Tiere.

The Rhine promenade and the Alter Zoll (Old Toll Station) are in direct neighbourhood of the city centre and are popular amongst both residents and visitors.

In the very south of the city, on the border with Wachtberg and Rhineland-Palatinate, there is an extinct volcano, the Rodderberg, featuring a popular area for hikes.

With Bonn being divided into two parts by the Rhine, three bridges are crucial for inner-city road traffic: the Konrad-Adenauer-Brücke (A562) in the South, the Friedrich-Ebert-Brücke (A565) in the North, and the Kennedybrücke (B56) in the centre.

In addition, regular ferries operate between Bonn-Mehlem and Königswinter, Bonn-Bad Godesberg and Königswinter-Niederdollendorf, and Bonn-Graurheindorf and Niederkassel-Mondorf.

[36] Other companies of supraregional importance are Weck Glaswerke (production site), Fairtrade, Eaton Industries (formerly Klöckner & Moeller), IVG Immobilien, Kautex Textron, SolarWorld, Vapiano and the SER Group.

The district of Bad Godesberg has established partnerships with Saint-Cloud in France, Frascati in Italy, Windsor and Maidenhead in England, UK and Kortrijk in Belgium; a friendship agreement has been signed with the town of Yalova, Turkey.