On this day, 110 years ago, on June 11, 1915 (April 29, 1915, the lunar calendar), China, Russia and Mongolia signed the "Treaty of Chaktu." Chinese representative Chen Lu (second from right in the front row) took a group photo with representatives of Russia and Mongolia at the Chaktu Conference. On June 7, 1915, China, Russia and Mongolia jointly signed the "China-Russia-Mongolia Treaty" in Chaktu. This is the final result since the Chaktu meeting between China, Russia and Mongolia on September 8, 1914. After the signing of the "China-Russia Declaration Document", in accordance with the provisions of the document, China, Russia and Mongolia met in Chaktu on September 8, 1914 to resolve various outstanding issues. The representative of China is Special Envoy Bi Guifang and Minister to Mexico Chen Lu, the representative of Russia is Consul General of Mongolia abroad, Mille, and the representative of Mongolia is Lama Dassizabu. The three parties each proposed a draft treaty, and the main points of dispute were on specific issues such as railways, postal services, tax rules, and judicial proceedings. On June 7, the three parties finally reached an agreement. The "Treaty of Chaktu" agreed that: Foreign Mongolia will recognize the China-Russia declaration document and other documents, and recognize the suzerainty of China; China and Russia will recognize the autonomy of Foreign Mongolia and will not station troops or colonize Foreign Mongolia; Outer Mongolia is still part of China's territory. The name of Bokdochebzundanba Hutuktu Khan is canonized by the President of the Republic of China. Outer Mongolia's official documents use the Republic of China's calendar, and also use the Mongolian cadres and branches to chronicle the years. Outer Mongolia has the right to handle all internal affairs and conclude industrial and commercial treaties with other countries, but has the right to conclude international treaties on political and land relations; Chinese merchants and citizens do not pay customs duties when transporting goods into Outer Mongolia, but they must pay various donations in accordance with local regulations; If there is a lawsuit between the people of China and Mongolia and China and Russia, it will be heard jointly by China and Mongolia and China and Russia; the Russia-Mongolia Trade Charter will continue to be effective. The treaty formally abolished the "independence" of Outer Mongolia and replaced it with "autonomy". However, Outer Mongolia still had the right to conclude relevant industrial and commercial treaties with foreign countries, and the Russia-Mongolia commercial treaty remained valid. On the day when the "Treaty" was signed, Yuan Shikai announced the canonization of Zhebuzundanba Hutuktu Khan. The titles of all Outer Mongolian princes and lamas would remain unchanged, and all those who participated in the independence of Kulun were pardoned. On the 9th, Living Buddha Kulun called the Beijing government to cancel the "independence" and the country's name. The Beijing government set up an Office of Chief Officials in Kulun and appointed Protector-General envoys, and set up Assistant Commissioners in Chaktu, Kovd, and Ulyyasutai., appointing assistant officials. China has restored nominal power to govern Mongolia, and the noisy issue of Mongolia has now come to an end.