|o Mayor||Thomas Schärer|
|o Total||92.85 km2 (35.85 sq mi)|
|Elevation||580 m (1,900 ft)|
|o Density||190/km2 (480/sq mi)|
|Time zone||CET/CEST (UTC+1/+2)|
|Dialling codes||07571, 07570 (Gutenstein), 07577 (Jungnau)|
The surrounding towns are on the north, Winterlingen (in the district of Zollernalb) and Veringenstadt, on the east, Bingen, Sigmaringendorf, and Scheer, on the south, Mengen, Krauchenwies, Inzigkofen, and Meßkirch, and on the west, Leibertingen, Beuron, and Stetten am kalten Markt. The city is made up from the following districts: Sigmaringen (inner-city), Gutenstein, Jungnau, Laiz, Oberschmeien and Unterschmeien.
In the 11th century, the end of the Early Middle Ages, the first castle was built on the rock that protected the valley. The first written reference is from 1077, when King Rudolf of Rheinfelden tried in vain to conquer Sigmaringen castle. The official city foundation was in 1250. In 1325 the city was sold to Ulrich III, Count of Württemberg. In 1460 and 1500, the castle was rebuilt into a chateau. About the county of Werdenberg Sigmaringen came in 1535 to the high noble family of the Hohenzollern.
From 1806 to 1849 Sigmaringen was the capital of the sovereign Principality Hohenzollern and residence of the princes of Hohenzollern. As a result of the Revolution in Sigmaringen of 1848, the Princes of Hechingen and Sigmaringen waived on their rule, whereby both principalities in 1850 fell to Prussia. From 1850 to 1945 Sigmaringen was the seat of Prussian Government for the Province of Hohenzollern. Karl Anton von Hohenzollern was 1858-1862 Prime Minister of Prussia. From 1914 to 1918 around 150 men from the town lost their lives during World War I. In the Nazi era a Gestapo office was in Sigmaringen. From 1937 it belonged to the Gestapo Stuttgart.
Between 1934 and 1942 more than 100 men were sterilized because of "hereditary diseases". During the Nazi medical murders, the "T4", became on 12 December 1940 for the first time 71 mentally handicapped and mentally ill patients victims of Nazi injustice. The deportation led them into the Grafeneck Euthanasia Centre, where the men and women were murdered as "unworthy of life". After the closure of Grafeneck in December 1940, on 14 March 1941 a further deportation to the Hadamar Euthanasia Centre was made.
On September 7, 1944, following the Allied invasion of France, Philippe Pétain and members of the Vichy government cabinet were relocated to Germany. A city-state ruled by the government in exile headed by Fernand de Brinon was established at Sigmaringen. There were three embassies in the city-state, representing each of Vichy-France's allies: Germany, Italy, and Japan.
French writers Louis-Ferdinand Céline, Lucien Rebatet and Roland Gaucher, fearing for their lives because of their political and anti-Semitic writings, fled along with the Vichy government to Sigmaringen. Céline's novel D'un château l'autre (English: Castle to Castle) describes the fall of Sigmaringen. The city was taken by Free French forces on April 22, 1945. Pétain returned voluntarily to France, where he stood trial for treason.
Three railways meet in Sigmaringen, the Danube Valley Railway leading from Donaueschingen to Ulm, the Tübingen-Sigmaringen railway from Tübingen to Aulendorf, and the line operated by the Hohenzollerische Landesbahn from Sigmaringen to Hechingen.
Sigmaringen lies in the serving area of Verkehrsverbund Neckar-Alb-Donau (NALDO).
Sigmaringen was the birthplace of Saint Fidelis of Sigmaringen, a Roman Catholic martyr of the Counter-Reformation in Switzerland, and Ferdinand of Romania, King of Romania. It was one of the residences of deceased Prince Friedrich Wilhelm of Hohenzollern-Sigmaringen, the late representative of the house, who was the first in the line of succession to the throne of Romania, by Salic law. Frederick Miller, founder of the Miller Brewing Company, was living in Sigmaringen during the start of his brewing career.