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In page Schleswig, Schleswig-Holstein:

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In 1544, Gottorf Castle became the residence of the local rulers. The dukes of Gottorf were vassals of the Danish kings and ruled over much of present-day Schleswig-Holstein. In 1721, when the Great Northern War ended, the dukes of Gottorf lost their power and their land became Danish crown land. After the Second Schleswig War (1864), Schleswig was annexed by the Kingdom of Prussia.[citation needed]