Hesse (Ger. Hessen), or HESSE-DARMSTADT, a grand-duchy of the German empire, lying between 7° 51' and 9° 39' E. long., and 49° 24' and 50° 50' N. lat. A strip of Hesse-Nassau divides it into a northern part, Oberhessen, completely enclosed by Prussia, and a southern part, comprising the two provinces of Starkenburg, east of the Rhine, and Rheinhessen, west of the Rhine. Besides these two main parts there are eleven enclaves in Baden and Prussia, the largest Wimpfen and Hohenstadt. Oberhessen is partly occupied in the east by the Vogelsberg, culminating in Taufstein (2532 feet), in the south-west by a ramification of the Taunus, the fertile and undulating valley of Wetterau lying between them. Starkenburg, in the south-east, is covered by the larger part of the Odenwald. The Bergstrasse divides the uplands of Starkenburg on the east from the plain of the Rhine on the west. This plain merges in the north into the plain of the Main. Rheinhessen, fertile and populous uplands, laid out largely in vineyards, the principal industry of the province, lies between the three points, Kreuznach, Mainz, and Worms. With the exception of the streams to the east of Vogelsberg draining into the Fulda, the waters of Hesse—Rhine, Main, Neckar, and Lahn—belong to the Rhine system. Of the total surface, comprising 3000 sq. m., 50 per cent. is tilled land and garden, and 31 forest. The most important products are corn—particularly in the Rhine and Main plains, and in Wetterau—pulse, potatoes, rape, poppy, tobacco, flax, fruit, and vines. Hesse yields iron, manganese ore, and peat. The industries—mainly in Mainz, Offenbach, and Worms—include the making of leather, boots, upholstery, tobacco, cigars, chemicals, &c. For an old Hessian trade, see MERCENARIES.
The total population amounted in 1875 to 882,349, in 1885 to 956,611, in 1890 to 992,883. Of these 419,642 belonged to Starkenburg, and 666,118 were Protestants, 293,632 Catholics, and 25,331 Jews. Mainz (q.v.) is the largest town; Darmstadt is the capital. Hesse has a university at Giessen, with 550 students, and a technical university at Darmstadt, with 300 students.—The government is constitutional, the legislative power consisting of two chambers. The annual revenue for the period 1894-97 was estimated at £1,721,000, and the expenditure at £1,570,000.
The Hesses were an ancient German tribe, and their territory came to be included in the principality of Thuringia. We first hear of the land-grave of Hesse in the 13th century. On the death of Philip the Magnanimous in 1567 the land-graviate of Hesse was quartered among his four sons, into Cassel, Marburg, Rheinfels, and Darmstadt. The House of Rheinfels becoming extinct in 1583, and that of Marburg in 1604, Hesse was reconstituted in two divisions—Hesse-Cassel and Hesse-Darmstadt. After the French Revolution Louis X., under pressure of France, signed a treaty of neutrality, and (1805-13) supplied Napoleon with a contingent of troops against the other Germans. In 1806 Louis assumed the title of grand-duke. In 1813, after the battle of Leipzig, Louis joined the allies, and in 1815 had to acknowledge the independence of Hesse-Homburg. In 1866 Hesse, having sided with Austria, had to yield up certain territories, including Hesse-Homburg, recently acquired, to Prussia. In 1820 was founded a new constitution of government, modified in 1856, 1862, and 1872.