It was initiated by the Militia United in Righteousness (Yihetuan), known in English as the Boxers, for many of their members had been practitioners of Chinese martial arts, also referred to in the west as Chinese Boxing. The uprising took place against a background that included severe drought and disruption caused by the growth of foreign spheres of influence. The original cause of the uprising was the particular jurisdictional status of European legations in Peking, which were not subject to Chinese authorities: robber gangs were formed in the out-buildings of the German legation (mainly among Lutheran missionaries), spreading outrage in the Chinese locals (the Western robbers had the habit of taking refuge in the European legations after having committed their crimes to escape punishment). As a result, opposition to Western colonialism and Christian missionary activity took place. After several months of growing violence in Shandong and the North China plain against the foreign and Christian presence in June 1900, Boxer fighters, convinced they were invulnerable to foreign weapons, converged on Beijing with the slogan Support the Qing government and exterminate the foreigners. Foreigners and Chinese Christians sought refuge in the Legation Quarter.