In the late 1890's, a secret Chinese group known as the Society of Righteous and Harmonious Fists (Yihequan),began rebelling against foreigners and Chinese Christians.
They would preform calisthenics rituals and martial arts that would supposedly give them "magical powers" that could protect them from bullet wounds and other types of attacks.
Moving on to the 1900's when the Boxer movement moved to Beijing killing various missionaries, Chinese Christians and destroying churches and railroad stations.
After the incident Austria-Hungary, France, Germany, Italy, Japan, Russia, the United Kingdom and the United States joined together with about 20,000 troops to attempt to stop the rebellions' and rescue the foreigners and Chinese Christians.
Since the other countries had more Artillery and soldiers, they managed to stop the Boxers and save the citizens. Those that were part of the rebellion group were punished.
The Chinese government had to sign an agreement known as the "Boxer Protocol." China didn't have permission to own any weapons for two years and had to pay $330 million to repair all the damage done by the Boxers.