THURGAU, a canton of north-east Switzerland, bordered by the Lake of Constance and, for a short distance, by the Rhine below the lake. It is in contact with Schaffhausen and Zurich to the west and St. Gall to the south. Thurgau is divided into three well-wooded hill masses running north-west to south east by the middle course of the river Thur (rising in the Toggen burg, q.v.) and by its affluent, the Murg.
The canton is traversed by the main railway line from Winter thur to Romanshorn (with branches to Constance, to the Toggen burg and to St. Gall) ; another important line extends from Ror schach along the lake shore via Constance, thence to Schaffhausen. The canton is a highly prosperous agricultural area, and though termed the "garden and granary of Helvetia" it also possesses an important cotton-spinning, dyeing and printing industry. The population in 1930 was 136,063. Of this 132;448 were German speaking, 2,687 were Italian-speaking and 578 were French-speak ing, while there were 90,634 Protestants, 44,584 Catholics and 142 Jews. Its capital is Frauenfeld on the Murg, population 1920, 8,711. Other towns are Arbon (9,393), Kreuzlingen and Romans horn (6,474), which is the chief lake port of the canton.
In 1798 it became free, and was one of the 19 cantons of the Helvetic republic, being formally received (like the other "subject lands") as a full member of the Swiss Confederation in 1803 by the Act of Mediation. The very advanced Cantonal Constitution dates to 1869. (See SWITZERLAND. Government.)