der Croon strengthened the fortifications of Plzeň from 1645 to 1649. Swedish troops passed the town in 1645 and 1648 without attacking it. The town and region have been staunchly Catholic despite the Hussite Wars. From the end of the 17th century, the architecture of Plzeň has been influenced by the Baroque style. The city centre has been under cultural heritage preservation since 1989. 19th century In the second half of the 19th century Plzeň, already an important trade centre for Bohemia, near the Bavarian/German border, began to industrialise rapidly. In 1869 Emil Škoda founded the Škoda Works, which became the most important and influential engineering company in the country and a crucial supplier of arms to the Austro-Hungarian Army. By 1917 the Škoda Works employed over 30,000 workers. After 1898 the second largest employer was the National Railways train workshop, with about 2,000 employees: this was the largest rail repair shop in all Austria-Hungary. Between 1861 and 1877, the Plzeň railway junction was completed and in 1899 the first tram line started in the city. This burst of industry had two important effects: the growth of the local Czech population and of the urban poor. After 1868 first Czech mayor of the city was elected. World War II Following Czechoslovak independence from Austria-Hungary in 1918 the German-speaking minority in the countryside bordering the city of Plzeň hoped to be united with Austria and were unhappy at being included in Czechoslovakia. Many allied themselves to the Nazis after 1933 in the hope that Adolf Hitler might be able to unite them with their German-speaking neighbours. Following the Munich Agreement in 1938, Plzeň became literally a frontier town; the creation of the Sudetenland moved Nazi Germany's borders to the city's outer limits. During the German occupation from 1939 to 1945, the Škoda Works in Pilsen was forced to provide armaments for the Wehrmacht, and Czech contributions, particularly in the field of tanks, were noted. The Germans operated a Gestapo prison in the city, and a forced labour camp in the Karlov district. Between 17 and 26 January 1942, over 2,000 Jewish inhabitants, most of Plzeň's Jewish population, were deported by the Nazis to the Theresienstadt concentration camp. The German-speaking population was expelled from the city after the end of the war in 1945, according to the provisions of the Potsdam Agreement. All of their property was confiscated. On 6 May 1945,