[1] Holstein-Pinneberg was one of the territories partitioned from the County of Holstein-Itzehoe (the others being Holstein-Rendsburg and Holstein-Plön) following the death of Gerhard I.
This resulted in the Pinneberg line of the Counts of Schauenburg and Holstein, who were called Holstein-Pinneberg or Holstein-Schauenburg.
In 1375, Prince-Archbishop Albert II of Bremen mortgaged the Haseldorfer Marsh to Adolphus VII.
The prince-archbishop of Bremen later failed to redeem the mortgage, and the Haseldorfer Marsh has been part of Holstein ever since.
The following counts ruled over Schaumburg and Holstein-Pinneberg: Circles est.