The County of Dannenberg (German: Grafschaft Dannenberg) was a fief in the Duchy of Saxony. Its heartland was largely identical with the present-day collective municipality of Elbtalaue in north Germany.
Its historical origins go back to the middle of the 12th century, when Henry the Lion founded the five counties of Holstein, Ratzeburg, Schwerin, Dannenberg and Lüchow during the Ostsiedlung, or colonisation of the East, from the mouth of the River Elbe to the southern border of the March of Brandenburg, in order to protect the new regions and borders of his territory.
The County of Dannenberg is first mentioned in the records in 1153; its first count, until 1169, was Volrad I of Dannenberg. He came from a noble family, the Edlers of Salzwedel. The county lasted until 1303, when the last count, Nicholas of Dannenberg, relinquished all his rights between the Elbe and Jeetzel rivers to Duke Otto the Strict, and it is finally mentioned in the records in 1311.
At that time farmers, craftsmen and artisans settled around the county castle and the village of Dannenberg emerged, although the name Dannenberg had existed previously. From 1223 to 1225 King Valdemar II of Denmark and his son were imprisoned by the count in the castle tower (Valdemar Tower), still preserved today, after Henry of Schwerin had brought them here. In 1303 the last count, Nicholas, ceded the county for an annuity of 40 marks to the Duke of Brunswick and Lüneburg, Otto the Strict. From that time the former county belonged to the Principality of Lüneburg. In 1306 the Dannenberg line died out. At the beginning of the 15th century Dannenberg was split off again as a form of compensation for the new line, but the reigning duke in Celle retained specific sovereign rights.