The ruling family became extinct in 1582, and the central and southern parts of the county were annexed by the Lüneburg branch of the duchy of Brunswick-Lüneburg.

Since this early mention spoke of Nienburg (= new castle), some kind sort of fortress must already have existed there for some time, perhaps in order to protect the crossing of the Weser.

The emblem of the war - like Counts of Hoya - a black bear-paw - still appears today in certificates and documents, and has also been taken over in the arms and seal of the town.

From those times the legend of the "Wähligen Rott" derives, a band of defenders who sortied from the town and took a banner and other great booty from Tilly's besieging forces a tent.

The banner and the tents are still displayed today at the annual "Scheibenschießen" (shooting tournament), a local festival with a tradition of over 600 years.

With its population of around 33,000 people, the town of Nienburg/Weser is today the economic and cultural centre of the otherwise empty area between the two major conurbations of Hannover and Bremen.