Schleswig-Holstein-Hadersleben was a branch line of the House of Oldenburg

House of Oldenburg

The House of Oldenburg is a North German dynasty and one of Europe's most influential Royal Houses with branches that rule or have ruled in Denmark, Russia, Greece, Norway, Schleswig, Holstein, Oldenburg and Sweden...

, and of the territory held by the Duke of this branch.

It was founded in 1544 by John II

John II, Duke of Schleswig-Holstein-Haderslev

John the Elder was the only Duke of Schleswig-Holstein-Haderslev. The predicate the Elder is sometimes used to distinguish him from his nephew John the Younger, who held Sønderborg from 1564 as a partitioned-off duke...

, as was compensated for not inheriting the Danish throne, with parts of Schleswig and Holstein. John II died childless in 1580, and the line died out with his death.

The territory consisted of the Ämter Haderslev

Haderslev

Haderslev is a town and municipality on the east coast of the Jutland peninsula in south Denmark. Also included is the island of Årø as well as several other smaller islands in the Little Belt. The municipality covers and has a population of 56,414 . Its mayor is Jens Christian Gjesing,...

, including Tørning, Tønder

Tønder

Tønder is a municipality in Region of Southern Denmark on the Jutland peninsula in south Denmark. The municipality covers an area of 1,278 km², and has a total population of 40,367...

 and Løgumkloster

Løgumkloster

Løgumkloster , is a town in Tønder municipality in Region of Southern Denmark on the Jutland peninsula in south Denmark with a population of 3,618...

 and this islands of Nordstrand, Germany

Nordstrand, Germany

Nordstrand is a peninsula and former island in North Frisia on the North Sea coast of Germany. It is part of the Nordfriesland district in the federal state of Schleswig-Holstein. Its area is 50 km², and its population is 2,300...

 and Fehmarn

Fehmarn

Fehmarn is an island and - since 2003 - a town on this island in the Baltic Sea, off the eastern coast of Schleswig-Holstein, Germany, and ca. 18 kilometers south of the Danish island of Lolland...

 in Schleswig, plus Rendsburg

Rendsburg

Rendsburg is a town on the River Eider and the Kiel Canal in the northeastern part of Schleswig-Holstein, Germany. It is the capital of the Kreis of Rendsburg-Eckernförde. As of 2006, it had a population of 28,476.-History:...

 and some smaller communities in Holstein

Holstein

Holstein is the region between the rivers Elbe and Eider. It is part of Schleswig-Holstein, the northernmost state of Germany....

, and after 1559 the middle part of Dithmarschen

Dithmarschen

Dithmarschen is a district in Schleswig-Holstein, Germany. It is bounded by the districts of Nordfriesland, Schleswig-Flensburg, Rendsburg-Eckernförde, and Steinburg, by the state of Lower Saxony , and by the North Sea.-Geography:The district is located on the North Sea...

.