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.

In 1303 the last count, Nicholas, ceded the county for an annuity of 40 marks[3] to the Duke of Brunswick and Lüneburg, Otto the Strict.

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.

[5] The coat of arms of the County of Dannenberg was emblazoned with lions rampart, sometimes separate, sometimes as a facing pair.

[2] Most of the information in this article comes from Geschichte der Grafen von Ratzeburg und Dannenberg (Meyer (1911) below).