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 are ...

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 so ...

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 betwe ...

The mountain is west of the city of

Singen Singen (Low Alemannic German, 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 ...

and 20 miles (30 km) from

Lake Constance Lake Constance (german: Bodensee, ) refers to three Body of water, 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, ca ...

. 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 Hohentwiel Castle is a ruin of a former castle on the peak of the dead volcano Hohentwiel. It is located in the region called Hegau, which is close to the Lake Constance, Lake of Constance. The mountain overtowers the city of Singen, which is loc ...

, whose ruins are on top of Hohentwiel, was built in 914 using stone taken from the mountain by

Burchard II, Duke of Swabia Burchard II (883/88429 April 926) was the Hunfriding Duke of Swabia (from 917) and Count of Raetia. He was the son of Burchard I of Swabia and Liutgard of Saxony. Burchard took part in the early wars over Swabia. His family being from Francon ...

. Originally, the Monastery of St. Georg was within the fortress, but in 1005 it was moved to

Stein am Rhein Stein am Rhein (abbreviated as Stein a. R.) is a historic town and a municipality in the canton of Schaffhausen in Switzerland. The town's medieval centre retains the ancient street plan. The site of the city wall, and the city gates are preserve ...

(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 Hans Müller, also known as Hans Müller von Bulgenbach, (c.1490 – 12 August 1525 in Laufenburg, Switzerland, Habsburg-Laufenburg), was a peasant leader during the German Peasants' War. After a career in the French military, he played a pivotal ...

, 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, Texa ...

sieges in the

Thirty Years' War The Thirty Years' War was one of the longest and most destructive conflicts in European history The history of Europe is traditionally divided into four time periods: prehistoric Europe (prior to about 800 BC), classical antiquity (80 ...

, 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 Counter-Reformation (), also called the Catholic Reformation () or the Catholic Revival, was the period of Catholic resurgence that was initiated in response to the Protestant Reformation. It began with the Council of Trent (1545–1563) a ...

. 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