(Germ. Sachsen-Weimar-Eisenach), a grand duchy of Germany, lying between N. Lat. 50° 25' and 51° 27'; E. Long. 9° 24' and 11° 49', consists of three principal portions, besides other smaller districts. The most westerly of these, the principality of Eisenach, is bounded on the N. by Prussia; E. by Saxo-Coburg-Gotha and Saxo-Meiningen; S. by Bavaria; and W. by Hesse-Cassel; the central and largest portion, on the W., N., and N.E. by Prussia; S.W. and S. by Altenburg and Schwartzburg; and the third portion lies between the larger part of Reuss on the S., and Altenburg, with a smaller part of Reuss, on the N.; and between Saxony on the E., and Schwartzburg on the W. The area and population of the various parts are as follows:

| Principality | Circles | Sq. miles | Pop. (1855) | |--------------|---------|-----------|-------------| | Eisenach | Eisenach | 666 | 80,551 | | Weimar | Weimar | 691 | 135,178 | | | Neustadt| 241 | 48,023 | | Total | | 1,398 | 283,755 |

The surface is generally undulating; and in some parts, especially in Eisenach, rises into mountains; there are also level tracts of land along the banks of the rivers. In a small separate portion of the grand duchy, the district of Ilmenau, near the S.E. extremity of the Thuringian Forest, rises Hinkelstein, the highest summit in the country, to the height of nearly 2700 feet. Eisenach is occupied in the north by the Thuringian Mountains, more than 1300 feet high; and in the south by those of Rhön, whose highest point, that of Ellenbogenberg, has an altitude of about 2500 feet. The circle of Neustadt is traversed by several offsets of the Erz Mountains, stretching from S.E. to N.W. Among the rivers which water the grand duchy is the Saale, traversing the E. of Weimar, and receiving the Ilm, which rises in Ilmenau, and traverses the circle of Weimar. The Saale also receives the Elster and the Orla, which are the chief rivers in the circle of Neustadt. The principality of Eisenach is watered by the Werra, and by its affluents, the Fulda, Ulster, Suhl, and Orsel. In most parts of the country the climate is temperate, and the air pure and healthy. Cold and raw weather frequently occurs in the mountainous regions; while in the valley of the Saale it is extremely pleasant. In spite of many difficulties which the nature of the soil offers to the cultivator, farming is carried on with much diligence and success. The quantity of corn raised frequently exceeds the demand; potatoes, pulse, hemp, flax, hops; and on the banks of the Saale, vines are also grown. A valuable article of produce is timber. The amount of arable land in the country is about 495,300 acres; of meadow land, 81,400 acres; of gardens and vineyards, 18,750 acres; and of forests, 225,250 acres. Among the live stock of the country, the chief are sheep, of a good breed, especially in the circle of Weimar, and horned cattle, in those of Neustadt and Eisenach. In all, the grand duchy contains more than 12,000 horses, 112,000 horned cattle, 236,000 sheep, 60,000 swine, and 13,000 goats. Of the mineral produce of the land, coal, iron, copper, cobalt, and marble, are the most important articles. The chief manufactures of the country are those of woollen, linen, and cotton cloth; dyeing, and the working of metals. The greatest amount of manufacturing industry exists in the circle of Eisenach, though Neustadt is the principal seat of the wool-manufacture. Wool and grain form the staple of a trade which is actively carried on. The chief of the educational establishments in the grand duchy is the University of Jena, which belongs equally to the other Saxon duchies. (See JENA.) Besides this there are 2 gymnasia, 2 normal seminaries, and, in addition to various other establishments, 460 elementary schools. The constitution is a limited monarchy, hereditary in the male line. The executive power is in the hands of the grand duke, and the legislative is shared with a diet, consisting of 31 deputies; of whom 21 are elected by universal suffrage, 4 by those who possess landed property of the annual value of L.145, 5 by those who have a revenue of the same amount from other sources, and 1 by the nobility who possess estates. Justice is administered by an upper court of appeal at Jena, whose authority extends over all the Saxon duchies, the principalities of Reuss and Schwartzburg, and the duchy of Anhalt-Dessan-Cöthen. Beneath this there is an appeal court at Eisenach, and various subordinate tribunals. The grand duke, and the majority of his subjects, belong to the Evangelical Church; but there are also about 10,000 Roman Catholics, and 1430 Jews, in the country. For the financial period, 1857-59, the annual revenue of the state was estimated at L.224,757, and the expenditure at L.223,902; while the public debt, Jan. 1, 1855, amounted to L.916,259. The territories of this state, which formerly belonged to the electorate of Saxony, fell to the lot of the Ernestine line at the partition in 1485.

After the deposition of John Frederick I. in 1547, numerous divisions took place among the different branches of the family; the right of primogeniture having been only introduced at a later period among these states. At the first of these divisions, in 1566, Weimar, with Gotha for its capital, was given to John Frederick II., eldest son of the deposed elector; and the rest of the country, under the name of Thuringia, to John William, his second son. The latter, however, after his brother had, by attempting to regain the dignity, incurred the fate of his father, obtained possession of Weimar, leaving Coburg and Eisenach to his two nephews, whose families became extinct in 1638. John William left two sons, the elder of whom founded the old Altenburg line; while the younger, John, had eleven sons, among whom were William, the immediate ancestor of the present family of Weimar, and Ernest, of all the other ducal houses. After this period the line of Weimar was not mixed up in the various divisions that took place among the other duchies, though it was itself once more subdivided, in 1672, into Weimar, Eisenach, and Jena. But these were reunited by the extinction of the line of Jena in 1690, and of that of Eisenach in 1741; while, in 1719, the right of primogeniture was introduced, which put an end to all further subdivisions. The most celebrated duke of Saxo-Weimar, in recent times, was Charles Augustus (1758-1828), who acted the part of a Macceans towards the science, art, and literature of Germany, took part in the contest against Napoleon, and received at the congress of Vienna, in 1815, along with the title of grand duke, several additions to his dominions.