Cause:
The Chinese still held the doctrine that no political relations or dealings should be held with any foreign country. The British Government under Palmerston decided to place trade relations with China on a more satisfactory basis, confusion and annoyance having arisen owing to the expiry of the East India Company’s charter. They also resolved to protect the opium traffic in spite of the protests of the Chinese Government. This latter reason overshadowed the others, and the war, which was known as the Opium War, was the subject of heated controversy in England.