The Boxer Rebellion, also known as the Boxer Uprising, the Boxer Insurrection, or the Yihetuan Movement, was an anti-foreign, anti-colonial, and anti-Christian uprising in China between 1899 and 1901, towards the end of the Qing dynasty, by the Society of Righteous and Harmonious Fists (Yhqun), known as the "Boxers" in English because many of its members had practised Chinese martial arts, which at the time were referred to as "Chinese boxing".

After the Sino-Japanese War of 1895, villagers in North China feared the expansion of foreign spheres of influence and resented the extension of privileges to Christian missionaries, who used them to shield their followers. In 1898 Northern China experienced several natural disasters, including the Yellow River flooding and droughts, which Boxers blamed on foreign and Christian influence. Beginning in 1899, Boxers spread violence across Shandong and the North China Plain, destroying foreign property such as railroads and attacking or murdering Christian missionaries and Chinese Christians. The events came to a head in June 1900 when Boxer fighters, convinced they were invulnerable to foreign weapons, converged on Beijing with the slogan "Support the Qing government and exterminate the foreigners." Diplomats, missionaries, soldiers and some Chinese Christians took refuge in the diplomatic Legation Quarter. An Eight Nation Alliance of American, Austro-Hungarian, British, French, German, Italian, Japanese and Russian troops moved into China to lift the siege and on June 17 stormed the Dagu Fort, at Tianjin. The Empress Dowager Cixi, who had initially been hesitant, now supported the Boxers and on June 21, issued an Imperial Decree declaring war on the invading powers. Chinese officialdom was split between those supporting the Boxers and those favouring conciliation, led by Prince Qing. The supreme commander of the Chinese forces, the Manchu General Ronglu (Junglu), later claimed he acted to protect the foreigners. Officials in the southern provinces ignored the imperial order to fight against foreigners.

The Eight-Nation Alliance, after initially being turned back by the Imperial Chinese military and Boxer militia, brought 20,000 armed troops to China. They defeated the Imperial Army in Tianjin and arrived in Beijing on August 14, relieving the fifty-five day siege of the Legations. Plunder of the capital and the surrounding countryside ensued, along with summary execution of those suspected of being Boxers in retribution. The Boxer Protocol of September 7, 1901, provided for the execution of government officials who had supported the Boxers, provisions for foreign troops to be stationed in Beijing, and 450 million taels of silver more than the government's annual tax revenueto be paid as indemnity over the course of the next 39 years to the eight nations involved. The Qing dynasty's handling of the Boxer Rebellion further weakened their control over China, and led the dynasty to attempt major governmental reforms in the aftermath.

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 were determined to expunge foreign influence from China. The Allied forces consisted of about 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 in 1901 with the signing of the Boxer Protocol.