The opening shot in the First Opium War, called the Battle of Kowloon （九龍海戰）, occurred on September 4, 1839, when the British ships opened fire on the Chinese war junks.
After the destruction of opium at Humen, the British merchants retreated （撤退）to one of the offshore islands not far from the mouth of the Pearl River. By July 1839, there were an estimated 50 British opium ships anchored （拋錨）around Hong Kong. These ships used Kowloon’s harbour to pick up fresh water and supplies.
On 7 July 1839, a party of drunken British sailors landed on the shore and got into a fight with local villagers in Tsim Sha Tsui. A local named Lin Weihe（林維喜） was beaten in a drunken brawl（毆鬥）and died the next day. The British sailors got back to their ships. This incident is known as the Murder of Lin Weixi （林維喜命案）in history.
Imperial Commissioner（欽差大臣） Lin Zexu (林則徐) demanded that the British hand over the “murderers”. But Charles Elliot (查理•義律), Chief Superintendent of British Trade in China, did not agree. He did not wish the British subjects（國民）to be tried（審訊）in the Chinese legal system, so he refused to turn the accused men over to the Chinese courts. Elliot instead held a trial（審判） for the accused men aboard a warship at sea. He himself served as the judge and merchant captains served as jurors（陪審團）. The naval court convicted（宣判…有罪）five sailors of assault（襲擊）and rioting, and sentenced them to fines along with hard labour in Britain. This verdict（裁决）, however, would later be overturned in British courts.
In response, Lin Zexu cut off food supplies to the British ships in an attempt to force Elliot to turn over the “murderers”. Chinese war junks were deployed（部署）to the mouth of Pearl River.
A long-simmering (醞釀已久的)conflict over the opium trade finally exploded into open warfare. On September 4, Charles Elliot led a small fleet of ships to demand food and fresh water. When these were not forthcoming, he ordered an attack on the Chinese junks. The junks returned fire. From their military stronghold（據點）in Kowloon, the Chinese forces were able to use their guns to repel the first wave of invading British ships. Nightfall ended the battle. The British ships retreated（撤退）. This was the first armed conflict of the First Opium War and is known as the Battle of Kowloon.
Tension mounted. The murder of Lin Weixi triggered（引發）the First Opium War in 1839. China suffered a humiliating（屈辱的）defeat, and as a result the British claimed possession（佔領）of Hong Kong island in 1841.