Sheng Xuanhuai
In October 1901, Mackay was appointed His Majesty´s Special Commissioner to conduct negotiations with representatives of China, arriving in Shanghai in early December for negotiations. The following year he and Chinese statesman Sheng Xuanhuai negotiated the Sino-British "Mackay Treaty," which anticipated the abolition of extraterritoriality in China. By late July 1902 the negotiations were reported as practically concluded when the British team arrived back in Shanghai, and the treaty was signed by Mackay and Sheng Xuanhua as representatives of their governments on 5 September 1902.