The Eight-Nation Alliance was a multinational military coalition that invaded northern China in 1900 with the stated aim of relieving the foreign legations in Beijing, then besieged by the popular Boxer militia, who had determined to expunge foreign influence from China. The Allied forces consisted of approximately 45,000 troops from the eight nations of Germany, Japan, Russia, Britain, France, the United States, Italy, and Austria-Hungary. Neither the Chinese nor the foreign allies issued a formal declaration of war. No treaty or formal agreement bound the Alliance together. Some western historians define the first phase of hostilities, starting in August 1900, as "more or less a civil war", though the Battle of the Taku Forts in June pushed the Qing government to support the Boxers. With the success of the invasion, the later stages developed into a punitive expedition, which pillaged Beijing and North China for more than a year. The fighting ended with the signing of the Boxer Protocol.