DANNEWERK, or DANEWERK (Danish, Dannevirke or Danevirke, " Danes' rampart ")  , the ancient frontier rampart of the Danes against the Germans, extending 1o2 m. from just south of the town of Schleswig to the marshes of the river Trene near the village of Hollingstedt . The rampart was begun by Gutsob'r (Godefridus), king of Vestfold, early in the 9th century . In 934 it was passed by the German king Henry I., after which it was extended by King Harold Bluetooth (940-986), but was again stormed by the emperor Otto II. in 974 . The chronicler Saxo Grammaticus mentions in his Gesta Danorum the " rampart of Jutland " (Jutiae moenia) as having been once more extended by Valdemar the Great (1157-1182), which has been cited among the proofs that Schleswig (Sc/nderjylland) forms an integral part of Jutland (Manuel hist. de la question de Slesvig, 1906) . After the union of Schleswig and Holstein under the Danish crown, the Danevirke fell into decay, but in 1848 it was hastily strengthened by the Danes, who were, however, unable to hold it in face of the superiority of the Prussian artillery, and on the 23rd of April it was stormed . From 1850 onwards it was again repaired and strengthened at great cost, and was considered impregnable; but in the war of 1864 the Prussians turned it by crossing the Schlei, and it was abandoned by the Danes on the 6th of February without a blow . It was thereupon.destroyed by the Prussians; in spite of which, however, a long line of imposing ruins still remains . The systematic excavation of these, begun in 1900, hasyielded some notable finds, especially of valuable runic inscriptions (F. de Jessen, La Question de Slesvig, pp . 25, 44-50, &c.) . See Lorenzen, Dannevirke og Omegn (2nd ed., Copenhagen, 1864): H . Handelmann, Das Dannewerk (Kiel, 1885) ; Philippsen and Stinksen, Fi hrer durch das Danewerk (Hamburg, 1903) .