Trat is the easternmost province that borders Cambodia and edges into the Gulf of Thailand. The name is believed to be a play on Krat, an indigenous plant used for making brooms found in abundance in the province. During the reign of King Rama V (1865-1910), Trat was ceded to the French in exchange for withdrawal of French forces from neighboring Chanthaburi. It was later returned to Thailand when other provinces were given to the French in Cambodia in exchange. Open conflict with the French occurred on January 17, 1941 during the Indochina War when a French naval squadron encroached upon Thai territorial waters, resulting in the Koh Chang Naval Battle.