ANDERNACH, a town of Germany, in the Prussian Rhine province, on the left bank of the Rhine, 10 m. N.W. of Coblenz by the main line to Cologne. Pop. (1900) 7889. Viewed from the river it makes a somewhat gloomy, though picturesque, impression, with its parish church (a basilica dating from the 12th century, with four towers), the round watch-tower on the Rhine, old walls in places 15 ft. thick, and a famous crane (erected 1554) for lading merchandise. Among other buildings are a Gothic Minorite church (now Protestant), a town hall, and a prison, formerly the castle of the archbishops of Cologne. Andernach has considerable industries, brewing and manufactures of chemicals and perfumes, and has also a trade in corn and wine. But its most notable article of commerce is that of mill-stones, made of lava and tufa-stone, a product much used by the Dutch in the construction of their dykes.

Andernach (Antunnacum) is the old Roman Castellum ante Nacum, founded by Drusus and fortified in the 3rd century A.D. In 1109 Andernach received civic rights, passed in 1167 to the electors of Cologne, in 1253 joined the confederation of the Rhine cities and was the most southern member of the Hanseatic league. Here in 1474 a treaty was signed between the emperor Frederick III., the four electors of the Rhine and France. In 1794 Andernach passed to France, but in 1815 was ceded, together with the left bank of the Rhine, to Prussia.