Zongli Yamen for a commercial treaty with the Qing Empire. This was not at a very good time for China, since Britain and France had just invaded Beijing in the Second Opium War and the Xianfeng Emperor was still exiled in Chengde. The negotiations took three months and the Emperor died in late August. Finally on 2 September 1861, Count Eulenburg and Qing representative Chonglun signed a commercial treaty with the Qing Empire, which was modeled on the French Treaty of Tianjin. In the treaty, Prussia represented the whole German Customs Union and the treaty would govern Sino-German relations until World War I, when the treaty was repudiated by China. Siam When the expedition reached Siam, the delegation had been expected by King Mongkut for a year. He "expressed his delight and inquired about the number and size of the warships, immediately thereafter he asked if the Prussians maintained colonies or had the intention to acquire them." The question answered in the negative "consoled him: he was all the more delighted to gain new unselfish friends as the old ones just became difficult" (Fritz Count of Eulenburg). After a long stay, on 17 February 1862 Fritz Count of Eulenburg signed a Treaty in the name of Prussia, the States of the Customs Union and Mecklenburg. Legacy Several participants in the expedition, including Count Eulenburg himself, wrote accounts of the East Asian expedition. Ferdinand von Richthofen later remarked that of the 64 Naval officers who took part in the expedition, 23 went on to have substantial rank in later years. The photographic record of this visit to Japan opens a window which becomes unique reference source. Sesquicentennial The 150th anniversary of Japanese-German relations commemorates the Eulenburg expedition and both the short- and long-term consequences of the treaty of amity and commerce which was signed by Japanese and German negotiators. From autumn 2010 through autumn 2011, events were planned in Germany and in Japan hoping "to 'raise the treasures of our common past' in order to build a bridge to the future." See also Unequal treaty Notes Further reading Auslin, Michael R. (2004). Negotiating with Imperialism: The Unequal Treaties and the Culture of Japanese Diplomacy. Cambridge: Harvard University Press. ; OCLC 56493769 Bara, Xavier. "The Kishū Army and the Setting of the Prussian Model in Feudal Japan, 1860–1871." War in History 19.2 (2012): 153-171. https://doi.org/10.1177/0968344511432980 Dobson, Sebastian, & Sven Saaler. Under Eagles