One day in May 1880, a nearly seventy year old commander-in-chief left Suzhou (now Jiuquan City) on horseback and advanced westward, followed by a neatly advancing team of cavalry and infantry. In the queue, a carriage was particularly eye-catching, with a thick black coffin pulled on top of it. The commander carrying the coffin on the expedition was Zuo Zongtang, the imperial envoy appointed by the Qing government and the governor of Shaanxi and Gansu. The goal of his expedition was to recover Ili, Xinjiang, which had been occupied by the Tsarist Russia for many years. The statue of Zuo Zongtang is located in Zuo Park, Suzhou District, Jiuquan City, Gansu Province. (Image source: Party building in Suzhou) In 1865, the military officer Aguba of the Kokand Khanate (now Uzbekistan), adjacent to the northwest border of China, invaded Xinjiang and occupied the southern Xinjiang region, including Kashgar, Hotan, Aksu, as well as Dihua (now Urumqi), Turpan, and other places. At the same time, shortly after the end of the Crimean War, the focus of competition between Russia and Britain shifted to Asia. Xinjiang, located in the hinterland of Asia and Europe and vividly known as the "Asian hub" and "Asian heart", is becoming increasingly important in its geographical location. After learning about Aguba's invasion of Xinjiang, both Russia and Britain realized that this was a significant opportunity to expand their sphere of influence, so both countries supported Aguba to varying degrees. The Tsarist Russia invaded the Ili region under the pretext of "managing" and protecting overseas Chinese, and threatened to attack Dihua. The UK is attempting to establish a "buffer state" in Xinjiang to isolate the forces of the Tsarist Russia. With the support of Tsarist Russia and Britain, Aguba established a puppet regime, and the situation in the northwest border of China was precarious. The courtiers represented by Li Hongzhang advocated following the advice of Britain, acknowledging the fact that Aguba had occupied Xinjiang, and concentrating national efforts on coastal defense, which to some extent meant giving up Xinjiang. Upon learning of this situation, Zuo Zongtang was extremely anxious. He stepped forward like a lone warrior, insisting that giving up Xinjiang is a short-sighted act that undermines national power, encourages the arrogance of Western powers, and will inevitably suffer long-term consequences. He stated that the interests of "those who rebuild their territory protect Mongolia, and those who protect Mongolia protect the capital" ultimately moved the highest ruler of the Qing Dynasty. The Qing government thus established a strategy of placing equal emphasis on "coastal defense" and "border defense". In 1875, Zuo Zongtang, the Governor of Shaanxi and Gansu, was appointed as the Imperial Commissioner to oversee the military affairs of Xinjiang. It is difficult to raise food, raise salaries, and transport food. Xinjiang has a vast territory, with an area of 1.66 million square kilometers today, accounting for one sixth of China's land area. There are numerous grasslands, rivers, and contiguous deserts and Gobi here. The Taklamakan Desert in the southern Xinjiang region covers an area of 330000 square kilometers, making it the largest desert in China and the tenth largest desert in the world, known as the "Sea of Death". Today, China has built three highways that cross the Taklamakan Desert. But in the 1870s, the Western Expeditionary Army had no possibility of crossing the Taklamakan Desert. Faced with the complex terrain of Xinjiang, it is imperative to first recapture northern Xinjiang. The key to the war of recapturing Xinjiang lies in solving the supply problem. The use of troops in the northwest is difficult to raise salaries, raise grain, and transport. The journey from Gansu to Xinjiang is far away, and advance planning is necessary