Biebrich, Or Bieberich, a town of Prussia, in the province of Hesse-Nassau, on the right bank of the Rhine, 3 m. S. of Wiesbaden; pop. in 1871, including Mosbach, 6,642. The palace of Biebrich, a fine modern building, though somewhat dilapidated, has long been the summer residence of the dukes of Nassau, several of whom are buried in the church here. The adjoining gardens are very pretty and extensive, and accessible to the public. They contain fine alleys, famous greenhouses, and a large fountain; and within their circuit is a miniature castle built on the ruins of the old castle of Mosbach, on the bank of a small artificial lake. Many Roman antiquities were removed to the castle from the former abbey of Ebersbach. S. E. of Biebrich, in the direction of Castel (opposite Mentz), are traces of a Roman fort. Caesar in his second expedition against the Suevi, and Agrippa, are supposed by some authorities to have crossed the Rhine in this vicinity. Biebrich became a free port in 1831, and is accessible to steamers and large sailing, vessels.