The Anglo-Chinese Opium Wars began in November 1838 following a series of trade disputes between the two countries. In 1756 China had sought to limit trade between European merchants and its own civilians by implementing the Canton System, which placed restrictions on the ports at which trade could take place. In addition, it became increasingly difficult for Europeans to access trade routes within China. As a result, the British East India Company incurred considerable losses. It therefore looked to redress the problem by investing heavily in opium production. Consequently, large quantities of opium were shipped from Bengal to the coast of China and sold to Chinese smugglers in defiance of the law. In 1838 Emperor Dao Guang ordered the arrest of Chinese opium dealers and the confiscation of opium stocks from foreign companies. In response the British government sent forces from India to attack the Chinese coast. Eventually, the Treaty of Nanking brought an end to the First Opium War (1838–42). Further trade disputes relating to British access to Chinese ports led to the Second Opium War of 1856, which was concluded by the Treaty of Tientsin in 1860.