Hagen im Bremischen belonged to the
Prince-Archbishopric of Bremen, established as a territory of
imperial immediacy in 1180. The prince-archiepiscopal fortress (, ) dates back to the 12th century, probably Prince-Archbishop
Hartwig II initiated its construction. Since the 14th century the fortress has also been used as a residential castle by the Bremian prince-archbishops. The present structure was formed between 1502 and 1507 by Prince-Archbishop
Johann Rode. In the mid-16th century the inhabitants adopted Lutheranism. During the
Leaguist occupation under
Tilly (1628–1630), they suffered from attempts of reCatholicisation. In 1648 the Prince-Archbishopric was transformed into the
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. In 1807 the ephemeric
Kingdom of Westphalia annexed the Duchy, before
France annexed it in 1810. In 1813 the duchy was restored to the
Electorate of Hanover, which – after its upgrade to the
Kingdom of Hanover in 1814 – incorporated the duchy in a
real union and the ducal territory, including Hagen, became part of the new
Stade Region, established in 1823. ==Coat of arms==