It was built in the 12th century and used to be the seat of government of the Welf dukes .
Hardeg Castle ( German : Burg Hardeg ) is an old castle in the little Lower Saxon town of Hardegsen in the German county of Northeim .
Hardeg Castle was built in the 12th century and used to be the seat of government of the Welf dukes .
Hardeg Castle ( German : Burg Hardeg ) is an old castle in the little Lower Saxon town of Hardegsen in the German county of Northeim .