Christ from 1746 to 1747. Catholic Poles were later discriminated against, however. In 1758, during the Seven Years' War, POWs brought the plague to the city. The city's textile industry was booming by the end of the 1700s. By 1800, large parts of the city walls had been dismantled to allow the city to expand. The textile industry suffered during the 1820s while adjusting to the Industrial Revolution and an import ban by the Russian Empire. The city's economy began to recover after many clothiers emigrated to Congress Poland. English industrialists were among the 19th-century economic reformers of Zielona Góra. During industrialisation, many Germans from the countryside moved to large industrial cities and a large number of Poles came to German cities to work as well. The Polish population was pushed by Germanisation to rural villages, although some remained in the town contributed to the economic revival of the city. A Polish church remained functional until 1809 and a Polish craftsmen association (Towarzystwo Polskich Rzemieślników) was established by Kazimierz Lisowski in 1898; it existed till 1935 when Lisowski was murdered by the Gestapo. In 1923 a branch of the Union of Poles in Germany was established. In 1932 the German authorities did not allow the establishment of a Polish school. Since 1816 after the Napoleonic Wars, Grünberg was administered within the district Landkreis Grünberg in the Province of Silesia. In 1871 it became part of the German Empire during the unification of Germany. English industrialists purchased some of the city's textile factories during the 1870s and 1880s. By 1885, most of Grünberg's population of 14,396 were Protestants. The city was first connected to the Glogau (Głogów)-Grünberg (Zielona Góra)-Guben railway line in 1871, followed by connections to Christianstadt (Nowogród Bobrzański) in 1904, Wollstein (Wolsztyn) in 1905, and a local line to Sprottau (Szprotawa) in 1911. In 1919, Grünberg became part of the Province of Lower Silesia within Weimar Germany. On 1 April 1922 it became a district-free city, but this status was revoked on 1 October 1933 while part of Nazi Germany. During the Kristallnacht in 1938, the Germans destroyed the synagogue. During World War II the Germans established a women's subcamp of the Gross-Rosen concentration camp, 11 forced labour camps and 4 labour units of the POW camp in Żagań, intended for French, Italian and Soviet prisoners of war. When asked about the specifics of the city in mid-February 1945,