The Battle of Tysami refers to a military engagement involving a warship from the United Kingdom's China Squadron and the Chinese pirates of Chui A-poo. It was fought in September 1849 off Tysami, China in Harlaim Bay and ended with a Royal Navy victory. It was also the precursor engagement to the larger Battle of Pinghoi Creek where Chui A-poo's fleet was destroyed. Chui A-poo is said to have commanded over 500 junks in his career as an outlaw and was a follower of Shap Ng-tsai, another famed pirate of the era. Chui A-poo's base was in Bias Bay which is next to Harlaim Bay and was the location of his harbor and arsenal for constructing war-junks. In February 1849, Chui A-poo fled Hong Kong after killing two Europeans. The incident became known to the foreign population of the island who then pressured the Royal Navy to respond. During the time of the battles he commanded twenty-seven war-junks each mounting twelve to eighteen guns and displacing an average of 500 tons. All together ab