Thurgau (tōrˈgou) [key], canton (1993 pop. 213,200), 388 sq mi (1,005 sq km), NE Switzerland. Bordered in the north by Lake Constance and watered by the Thur River, Thurgau is a fertile and cultivated region. Cereals and fruit are grown, cattle are raised, and wine is produced. It has several industrial towns, notably Arbon and Frauenfeld, the capital of the canton. Manufactures include textiles, motor vehicles, and shoes. The population is mainly Protestant and German-speaking. Thurgau was acquired (1264) by the Hapsburgs and was conquered (1460) by the Swiss cantons; it was ruled by the cantons until 1798, when the French invaded Switzerland. In 1803 it became a canton of Switzerland.