Hohentwiel is an

extinct volcano A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often found where tectonic plates a ...

in the

Hegau The Hegau is an extinct volcanic landscape in southern Germany extending around the industrial city of Singen (Hohentwiel), between Lake Constance in the east, the Rhine River in the south, the Danube River in the north and the Randen—as the s ...

region of

Baden-Württemberg Baden-Württemberg (; ), commonly shortened to BW or BaWü, is a German state () in Southwest Germany, east of the Rhine, which forms the southern part of Germany's western border with France. With more than 11.07 million inhabitants across a ...

in southern

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwee ...

The mountain is west of the city of

Singen Singen ( Low Alemannic: ''Singe'') is an industrial city in the very south of Baden-Württemberg in southern Germany and just north of the German-Swiss border. Location Singen is an industrial city situated in the very south of Baden-Württember ...

and 20 miles (30 km) from

Lake Constance Lake Constance (german: Bodensee, ) refers to three bodies of water on the Rhine at the northern foot of the Alps: Upper Lake Constance (''Obersee''), Lower Lake Constance (''Untersee''), and a connecting stretch of the Rhine, called the Lak ...

. Hohentwiel began forming, along with the chain of volcanoes in the Hegau region, about 7–8 million years ago, when a layer of volcanic ash and stone was laid down. The magma consists of

phonolite Phonolite is an uncommon extrusive rock, of intermediate chemical composition between felsic and mafic, with texture ranging from aphanitic (fine-grained) to porphyritic (mixed fine- and coarse-grained). Phonolite is a variation of the igneous ...

. In the following millions of years, the core was opened 260 metres beneath the surface by the glaciers from the ice age. This formed the core that is now exposed, after the ensuing millions of years of erosion. Hohentwiel Castle, whose ruins are on top of Hohentwiel, was built in 914 using stone taken from the mountain by Burchard II, Duke of Swabia. Originally, the Monastery of St. Georg was within the fortress, but in 1005 it was moved to Stein am Rhein (now in

Switzerland ). Swiss law does not designate a ''capital'' as such, but the federal parliament and government are installed in Bern, while other federal institutions, such as the federal courts, are in other cities (Bellinzona, Lausanne, Luzern, Neuchâtel ...

), and the Swabian dukes lost control of Hohentwiel. In the later Middle Ages the noble families von Singen-Twiel (12th–13th centuries), von Klingen (to 1300) and von Klingenberg (to 1521) resided here. In 1521, it was passed on to Duke Ulrich von Württemberg, who developed Hohentwiel into one of the strongest fortresses of his duchy. During this time, it began to be used as a prison, and in 1526, Hans Müller von Bulgenbach, a peasant commander, was imprisoned there before he was executed. The fortress resisted five

Imperial Imperial is that which relates to an empire, emperor, or imperialism. Imperial or The Imperial may also refer to: Places United States * Imperial, California * Imperial, Missouri * Imperial, Nebraska * Imperial, Pennsylvania * Imperial, Texas ...

sieges in the

Thirty Years' War The Thirty Years' War was one of the longest and most destructive conflicts in European history, lasting from 1618 to 1648. Fought primarily in Central Europe, an estimated 4.5 to 8 million soldiers and civilians died as a result of batt ...

, under the command of Konrad Widerholt between 1634 and 1648. The effect was that Württemberg remained Protestant, while most of the surrounding areas returned to

Catholicism The Catholic Church, also known as the Roman Catholic Church, is the largest Christian church, with 1.3 billion baptized Catholics worldwide . It is among the world's oldest and largest international institutions, and has played a ...

in the Counterreformation. The castle served as a Württemberg prison in the 18th century and was destroyed in 1801 after being peacefully handed over to the French. Today the former fortress Hohentwiel is the biggest castle ruin in Germany. The modern city of

nestles at the foot of the mountain.

References

External links

virtual Hohentwiel tour
{{Authority control Extinct volcanoes Mountains and hills of Baden-Württemberg Volcanoes of Germany Miocene volcanoes Mountains and hills of the Hegau

See also

References

External links