World War, like many other cities in Europe, Częstochowa had a significant Jewish population: according to Russian census of 1897, out of the total population of 45,130, Jews constituted 12,000 (so around 26% percent). An anti-Semitic pogrom occurred in 1902. A mob attacked the Jewish shops, killing fourteen Jews and one gendarme. Częstochowa entered the 20th century as one of the leading industrial centres of Russian Poland (together with Warsaw, Łódź, and Zagłębie Dąbrowskie). The city was conveniently located on the Warta and other smaller rivers (Kucelinka, Stradomka, Konopka). Real estate and land prices were low, compared to Łódź. The monastery attracted numerous pilgrims, who also were customers of local businesses. In 1904, Częstochowa had 678 smaller workshops, which employed 2,000 workers. In 1902, rail connection to the Prussian border crossing at Herby Stare was opened, and in 1911, the line to Kielce was completed. The Revolution in the Kingdom of Poland (1905–1907) began in Częstochowa as early as May 1904, when first patriotic rallies took place. On December 25, 1904, a man named Wincenty Makowski tried to blow up a monument of Tsar Alexander II, which stood in front of the monastery. In February 1905, a general strike action was declared in the city, with workers demanding pay rises. In June 1905 street clashes took place in Częstochowa, in which 20 people were killed by Russian forces. Further protests took place in 1909 and 1912. World War I In early August 1914, Częstochowa was abandoned by the Imperial Russian Army, and the first units of the German Army entered the city on August 3. Four days later drunken German soldiers shot at each other; an unknown number died. Residents of the city were accused of killing Germans, and as a punishment, a number of civilians were executed. During the German occupation (1914–1918), Częstochowa was cut off from its prior Russian markets, which resulted in widespread poverty and unemployment. Furthermore, German authorities closed down several factories, urging unemployed workers to migrate to Upper Silesia, where they replaced men drafted into the army. Altogether, some 20,000 left for Upper Silesia and other provinces of the German Empire. On February 2, 1915, Częstochowa was visited by Charles I of Austria. Four days later Emperor Wilhelm II came to the city, and on May 17, 1915, Częstochowa hosted King of Saxony Frederick Augustus III. Unlike the city of Częstochowa, since April 26, 1915,