Amethyst incident: The People's Liberation Army attacks HMS Amethyst (F116) travelling to the British embassy in Nanjing during the Chinese Civil War.

The Amethyst incident, also known as the Yangtze incident, was a historic event that occurred on the Yangtze River for three months in the summer of 1949, during the late phase of the Chinese Civil War. The incident involved the Communist People's Liberation Army (PLA), who were in the process of a river-crossing offensive to overthrow the Nationalist Government, and four British Royal Navy ships HMS Amethyst, HMS Black Swan, HMS Consort and HMS London. The British warships, whose claimed right of passage along the Yangtze had been unchallenged previously since the 1858 Treaty of Tientsin with the late Qing dynasty, came under bombardment by PLA artillery and were forced to withdraw permanently from Chinese territorial waters.