The Unteraargau is the lower watershed of the Aar River in the Swiss canton of Aargau.

Geography

It corresponds approximately to the canton's southwestern districts of Aarau,

Brugg , neighboring_municipalities = Gebenstorf, Habsburg, Hausen, Holderbank, Lupfig, Riniken, Rüfenach, Schinznach, Untersiggenthal, Villigen, Villnachern, Veltheim, Windisch , twintowns = Rottweil (Germany) , website ...

, Kulm,

Lenzburg Lenzburg is a town in the central region of the Swiss canton Aargau and is the capital of the Lenzburg District. The town, founded in the Middle Ages, lies in the Seetal valley, about 3 kilometres south of the Aare river. Lenzburg and the neighb ...

and

Zofingen Zofingen (french: Zofingue) is a city in the canton of Aargau in Switzerland. It is the capital of the district of Zofingen. Zofingen is a walled city and home of an ancient monastic settlement. History In ancient times Zofingen was a settleme ...

. The Unteraargau includes that portion of the Aar valley between Aarau and the Klingnauer Stausee, as well as the Aar tributary valleys of the Aabach,

Suhre The river Suhre is a 34 kilometer long tributary of the river Aare in the Swiss cantons of Lucerne and Aargau. The river rises in Sempachersee (or Lake Sempach) at an elevation of 504 meters above sea level, and joins the Aare east of the town Aar ...

Wigger ''Wigger'', or ''wigga'', is a term for a white person of European ethnic origin, who emulates the perceived mannerisms, language, and fashions associated with African-American culture, particularly hip hop. The term is a portmanteau of ''whit ...

and Wyna rivers. It also includes some parts of the Jura Mountains.

History

The region was held by the Swabian

counts of Lenzburg The Counts of Lenzburg (also Counts of Baden by the early 12th century) were a comital family in the Duchy of Swabia in the 11th and 12th centuries, controlling substantial portions of the '' pagi'' of Aargau and Zürichgau. After the extinction ...

and Kyburg, in 1264 it fell to the

House of Habsburg The House of Habsburg (), alternatively spelled Hapsburg in Englishgerman: Haus Habsburg, ; es, Casa de Habsburgo; hu, Habsburg család, it, Casa di Asburgo, nl, Huis van Habsburg, pl, dom Habsburgów, pt, Casa de Habsburgo, la, Domus Hab ...

. It is sometimes called the Berner Aargau, with reference to its incorporation into the territory of Bern from 1415 to 1798. Until 1415, the region belonged to the

Further Austria Further Austria, Outer Austria or Anterior Austria (german: Vorderösterreich, formerly ''die Vorlande'' (pl.)) was the collective name for the early (and later) possessions of the House of Habsburg in the former Swabian stem duchy of south-wes ...

n possessions of Archduke Frederick IV of Habsburg. When he was outlawed by Emperor Sigismund of Luxembourg, his territories were forfeit. His former subjects agreed to acquire the land, and the Bernese citizens of the

Swiss Confederacy The Old Swiss Confederacy or Swiss Confederacy ( Modern German: ; historically , after the Reformation also , "Confederation of the Swiss") was a loose confederation of independent small states (, German or In the charters of the 14th century ...

were the first on the ground. The area was then consolidated with the

Oberaargau The Oberaargau is the region that encompasses the upper watershed of the Aar River in the canton of Bern in Switzerland. On the north, lie the Jura Mountains, and on the south the hills leading to the Emmental. Administratively, the Oberaargau fo ...

into one region after the conquest by the city of Bern. When Bern lost its old power with the invasion by French troops after the

French Revolution The French Revolution ( ) was a period of radical political and societal change in France that began with the Estates General of 1789 and ended with the formation of the French Consulate in coup of 18 Brumaire, November 1799. Many of its ...

in 1798, the Unteraargau became the modern canton of Aargau. The boundary between the Oberaargau and Unteraargau was fixed in 1798 along the Wigger River. In 1802, however, it was shifted west to the river Murg. This action was confirmed by the

Act of Mediation The Act of Mediation () was issued by Napoleon Bonaparte, First Consul of the French Republic on 19 February 1803 establishing the Swiss Confederation. The act also abolished the previous Helvetic Republic, which had existed since the invasi ...

Napoleon Napoleon Bonaparte ; it, Napoleone Bonaparte, ; co, Napulione Buonaparte. (born Napoleone Buonaparte; 15 August 1769 – 5 May 1821), later known by his regnal name Napoleon I, was a French military commander and political leader who ...

in 1803 and the

Congress of Vienna The Congress of Vienna (, ) of 1814–1815 was a series of international diplomatic meetings to discuss and agree upon a possible new layout of the European political and constitutional order after the downfall of the French Emperor Napoleon B ...

in 1815. {{Authority control Geography of Switzerland Aargau