Although Europeans had shown more interest in Canton than Shanghai early on for commercial advantages, the port's strategic position was key to British interests as the island nation declared war against China in 1839, starting the first Anglo-Chinese Opium War. The first settlement in Shanghai for foreigners was the British settlement, opened in 1843 under the terms of the Treaty of Nanking. This treaty forced the Qing Dynasty to make punitive territorial and economic concessions and would become the first of the unequal treaties imposed upon China by its fellow great powers. To the north, the settlement was bordered by the right bank of the Suzhou River before its inflow into the Huangpu River, which delineated the concession's eastern boundaries. To the south, the Yang-King-Pang channel marked the concession's southern limits which would later become the boundary between the British and French concessions.