On 116 years ago today, July 15, 1909 (May 28, 1909, the lunar calendar), China and Portugal began negotiations on the demarcation of Macao. On July 15, 1909, China and Portugal began negotiations on the demarcation of the Macao boundary in Hong Kong. The Chinese representative is Gao and modest, and the Portuguese representative is Masadou. After the arms smuggling case of the Japanese ship "Erchen Maru" occurred in 1908, the issue of Macao's boundary location arose. The Qing court advocated early determination of the Macao boundary. China businessmen in Xiangshan, Guangzhou and other places also requested the delineation of Macao's boundaries to protect their territory from embezzlement. As soon as the "Erchen Maru" negotiations were over, the Qing government sent Gao Erqian, the right-hand senator from the Ministry of Foreign Affairs, to Guangdong to investigate the boundary of Macao, and asked Portugal to send personnel to join the survey. At the beginning of the negotiations, Portugal sent more troops to Macau in an attempt to put pressure on China. During the negotiations, Masadou claimed that before Portugal invaded Macau, China had no real management of Macau. Macau and its affiliated areas should include the entire Macau Peninsula south of the Guanzhong Gate, plus Qingzhou, Shuizai, Coloane, Big and Small Hengqin Islands, Duianshan Islands and all nearby mountain islands and all sea surfaces, with a total area of 326 square kilometers. Gao Erqian believed that Macau was originally a land leased to the Portuguese by China, and the nearby islands were not ownerless. The boundary between Macau should be the boundary between Macau and the Qing government would take back the two islands of Shuizai and Luohuan.