The Mongol general Bayan was bent on eliminating the threat posed by Song remnants, so he led his troops in pursuit and attacked southern China. After Emperor Duanzong died of illness in 1278, the Song forces' morale started to dwindle and soldiers began to desert the army. Lu Xiufu brought Zhao Bing to Meiwei (梅蔚), Gangzhou (碙州), which is in present-day Mui Wo, Lantau Island, Hong Kong. There, Zhao Bing was enthroned as the new emperor under the era name "Xiangxing" (祥興); Gangzhou was also renamed "Xianglong County" (祥龍縣). They moved to Yamen (in present-day Xinhui District, Jiangmen, Guangdong Province) to evade the Mongols. The Mongols sent the general Zhang Hongfan to lead troops to attack Zhao Bing and the Song remnants, leading to the Battle of Yamen. The Song forces, led by Zhang Shijie, put up fierce resistance against the Mongols in a naval battle but were eventually all wiped out by the enemy. On 19 March 1279, after realising all was lost, Lu Xiufu carried the seven-year-old Emperor Zhao Bing to a cliff, where they committed suicide by throwing themselves into the sea. Zhao Bing's death marked the end of the Song dynasty. Zhao Bing's tomb is located in present-day Chiwan, Nanshan District, Shenzhen. According to the locals at the Guangdong Province, prior to the final battle with the Yuan forces at Yamen, Zhao Bing and the Song remnants sought shelter in a monastery at Chaozhou. The monastery's monks served an impromptu leafy greens soup made of leaf vegetable, edible mushrooms, and vegetable broth. The emperor loved the soup and named it "Protect the Country Dish" (護國菜). A later generation named it in English "Patriotic Soup". After Zhao Bing died, the preparation of the soup became a way to honor the last Song emperor.