Carlsburg, Weser

Carlsburg (also Carolus-Stadt or Carolsburg) was a 17th-century fortified town in Swedish Bremen-Verden at the confluence of the Weser and Geeste rivers, at the site of modern Bremerhaven, Germany.

The status of the city of Bremen however was uncertain, and Sweden was unable to gain control of the town in two subsequent wars, 1654 and 1666.

As Bremen itself was out of reach, a new town was built nearby, named Carlsburg after the Swedish king Charles XI.

Before the construction and settlement plans for Carlsburg could be realised, building work had to be interrupted in 1675, when an alliance of Brandenburg-Prussia, the Principality of Lüneburg, the Prince-Bishopric of Münster and Denmark attacked Swedish possessions in North Germany during the Bremen-Verden Campaign.

When Carlsburg was besieged for a second time in late October 1675, its weakened garrison, decimated by illness and a lack of food, quickly surrendered in January 1676 to Münster and Lüneburg troops.