The first treaty between China and Great Britain, known as the Treaty of Nanking, was signed on board the British warship "Cornwallis" beneath the walls of the city of Nanking on August 29th, 1842.

Among other provisions of the Treaty, the ports of Canton, Amoy, Foochow, Ningpo and Shanghai were opened to foreign trade and were to be known as Treaty Ports. It was agreed that fair tariff rates should be imposed.

On the basis of the treaty, Shanghai was declared open to foreign trade on November 14th, 1843.