The uprising began as an anti-foreign, anti-imperialist, peasant-based movement in northern China, in response to foreign westerners seizing land from locals, concession grabbing, and granting immunity to criminals who converted to Catholicism. The insurgents attacked foreigners, who were building railroads and violating Feng shui, and Christians, who were held responsible for the foreign domination of China. In June 1900, the Boxers entered Peking, and ransacked the area around the Foreign Legations. On 21 June, in response to the Western attack on the Chinese Dagu Forts, Empress Dowager Cixi declared war against all Western powers. Diplomats, foreign civilians, soldiers, and Chinese Christians were besieged during the Siege of the International Legations for 55 days. A coalition called the Eight-Nation Alliance comprising Austria-Hungary, France, Germany, Italy, Japan, Russia, Britain and the United States organized the Seymour Expedition with 2000 troops, including 116 Americans. They were repulsed by the Boxers at the Battle of Langfang. A much larger Allied force formed the Gaselee Expedition and it was successful due to internal rivalries among the Chinese forces.