Neuhaus an der Oste (in High German, in Low Saxon: Neehuus) is a municipality in the district of Cuxhaven, in Lower Saxony, Germany.

[2] In 1404 Prince-Archbishop Otto II erected a new fortress on the right bank of the Aue, then named "dat Nygehus" (the new house), becoming the eponym for the place.

On 9 June 1547 Count Albrecht von Mansfeld, commander of the Protestant forces in the Smalkaldic War, captured the fortress.

By this time the inhabitants adopted Lutheranism, also as a form of opposition against the spendthrift Prince-Archbishop Christopher, who broke contracts with the estates of the prince-archbishopric and acted against its constitution.

The war ended by the Peace of Westphalia in 1648, by which the ecclesiastical Prince-Archbishopric was transformed into the secular Duchy of Bremen, which was first ruled in personal union by the Swedish crown – interrupted by a Danish occupation (1712–1715) – and from 1715 on by the House of Hanover.