A central province of Prussia, consisting chiefly of the ancient mark of Brandenburg, bounded N. by Mecklenburg and Pomerania, E. by the provinces of Prussia and Posen, S. by Silesia and the kingdom of Saxony, and W. by Prussian Saxony, Anhalt, and Hanover; area, 15,402 sq. m.; pop. in 1871, 2,863,461, of whom about 70,000 were Roman Catholics, 40,000 Jews, and the remainder Protestants. It embraces the former territories of Priegnitz and Uckermark in the north, Havelland and Banim in the centre, Neumark in the east, and Mittelmark and Lower Lu-satia in the south. It is divided into the districts of Frankfort and Potsdam, which are subdivided into 31 circles. The chief towns are Berlin, Potsdam, Frankfort-on-the-Oder, Brandenburg, and Spandau. The principal streams are the Elbe, Oder, Havel, and Spree. The surface, which is mainly level, is dotted with numerous lakes, swamps, and morasses, many of which have been drained. The soil is generally sandy and poor, but near the lakes and streams rich land is found. The principal productions are buckwheat, rye, potatoes,wool, flax, tobacco, and honey. Manufacturing is extensively pursued, and the province is intersected by numerous railroads and canals.

Lime and gypsum are found. - Brandenburg was originally inhabited by various German tribes, chiefly of the Sue vie race, who were succeeded in its possession by Wends, Wiltzes, Obotrites, and other Slavs. These were subjected to the Frankish sway by Charlemagne, but subsequently recovered their independence, and carried on long feuds with their neighbors the Thuringians and Saxons, until parts of their territory were conquered about 927 by the emperor Henry the Fowler, who founded the Nordmark, or mark of Salzwedel (subsequently known as Altmark, and now forming the northern part of the Prussian province of Saxony). His son Otho I. founded the bishoprics of Brandenburg and Havelberg, and the German-ization of the country now kept pace with its Christianization, the Wends and other Slavs stubbornly contesting the possession of the territories E. of the Elbe. New marks were now successively erected by the emperors in the conquered territories. The subjection of the Slavs was completed by Albert the Bear, count of Ballenstedt, of the house of Ascania, who in 1133 was appointed by the emperor Loth aire margrave of the Nordmark. Albert conquered the Priegnitz territory and the Mittelmark, and assumed the title of margrave of Brandenburg. He founded many towns, and drew German and Flemish settlers into the country.

He was also made duke of Saxony, but was unable to maintain this possession against Henry the Lion. Without being himself endowed with the electoral dignity, he may be considered the founder of the electorate of Brandenburg. He died in 1170. His elder grandson, Otho II., ceded considerable territories to the ecclesiastical dominion of Magdeburg, but the younger, Albert II. (1206-1221), again enlarged Brandenburg. The same was done by his sons, John I. and Otho III., who after a united reign of nearly 40 years divided the marks, Stendal and Salzwedel becoming their capitals. John, the founder of the elder line, was the first to assume the dignity of elector. Among his successors was Waldemar (1308-1319), a warlike prince. His line became extinct in 1320, the younger three years earlier. A period of distraction and decay followed, during which Brandenburg came into the possession of the house of Bavaria, was disputed by a pseudo-Waldemar, and finally acquired by the house of Luxemburg, the emperor Charles IV. bestowing it successively on his sons Wenceslas and Sigismund. The last named, on his election as emperor in 1411, appointed Frederick of Hohenzollern, burgrave of Nuremberg and ancestor of the royal line of Prussia, administrator of Brandenburg, in 1415 made him elector, and on April 18, 1417, the new elector was solemnly inaugurated at Constance. (See Hohenzolleen, and Prussia.) II. A town of the above described province, in the district of Potsdam, on both sides of the Havel, 35 m.

W. S. W. of Berlin; pop. in 1871, 25,828. It has a cathedral of the 14th century, situated on an island in the river, a castle, gymnasium, council house, several schools and churches, a public library, a theatre, and hospitals. There are several breweries, and manufactories of woollens, linens, hosiery, paper, hats, leather, etc. The trade is considerable. The railroad from Berlin to Magdeburg crosses the town. The name both of the town and the province is derived from Brennibor or Branibor (forest castle), the Slavic name of the old castle conquered by Henry the Fowler.