What did the eleven nations mean?

The Eleven Powers at the time of the Treaty of Simchun referred to Great Britain, the United States, Japan, Russia, France, Germany, Italy, Austria-Hungary, Belgium, Spain, and the Netherlands The Treaty of Simchun, also known as the Peace Treaty of the Simchun States and the Beijing Protocol, was a peace agreement signed between the government of China's Qing Dynasty and Great Britain, the United States, Japan, Russia, France, Germany, Italy, Austria-Hungary, Belgium, Spain, and the Netherlands following the failure of the Boxer Rebellion, Eight-Power Allied Forces invaded Beijing and signed a peace agreement. It is considered one of a series of unequal treaties signed by China after the First Opium War. The treaty was signed on July 25, 1901, the year of the Xinchou, hence the name Xinchou. September 7 on the Western calendar, so there is a "nine seven national shame" said.