1911 Encyclopædia Britannica/Birkenfeld
BIRKENFELD, a town of Germany, capital of the principality of the same name, on the Zimmerbach, 25 m. S.E. of Trier and on the main line of railway from Bingerbrück to Neunkirchen. Pop. 2500. Close by, on an eminence, lie the ruins of the castle of Birkenfeld, dating from the 14th century, once the residence of the counts palatine of Zweibrücken. The town has an Evangelical and a Roman Catholic church, a grand-ducal high school and a hospital. Besides brewing and tanning, its industries include the manufacture of tobacco and chicory. There is also a considerable trade in cattle.
The Principality of Birkenfeld is hilly and well-forested; agriculture prospers on the cleared lands, and fruit is grown in the valley of the Nahe, the principal stream. Ironstone and roofing slates are quarried, and there is some industry in agate-polishing and the manufacture of trinkets. The principality has an area of 312 sq. m. and a population (1900) of 43,409, chiefly Protestants. It is formed out of the former lordships of Dachstuhl and Oberstein, of part of the ancient countship of Sponheim, and sections of the duchy of Jülich, which were granted to the grand-duke of Oldenburg by the congress of Vienna in 1815. It is entirely an enclave in Prussian territory, and though it is represented in the Oldenburg diet, it is governed by a separate Regierungskollegium, consisting of a president and two members, who are responsible to the Oldenburg ministry.