After Gerhard I's death in 1290 his three younger sons partitioned Holstein-Itzehoe and Schaumburg into three branches, with Adolph VI the Elder, the third brother, getting Holstein-Pinneberg and Schaumburg south of the Elbe, the second brother Gerhard II the Blind getting Holstein-Plön, and the fourth Henry I receiving Holstein-Rendsburg.
In 1110, Adolf I, Lord of Schauenburg was appointed by Lothair, Duke of Saxony to hold Holstein and Stormarn, including Hamburg, as fiefs.
Ernst of Schaumburg (September 24, 1569 – January 17, 1622) was the first of the Counts of Schauenburg and Holstein-Pinneberg to earn the title of Prince, in 1619.
She was the only child of Herman III, Count of Celje (b. 1380? - d. after falling from his horse, 30 July 1426), by his first wife, Elisabeth (b. 1377? - d. bef. 1423), daughter of Baron Johann II of Abensberg and widow of Ulrich II of Schauenburg.
However, with respect to his elder brothers Cologne's Archbishop-Electors Adolphus III (reg. 1547–1556) and Anthony I (reg. 1557-1558) he refrained from open confrontation.
Adelaide of Holstein-Rendsburg (died January 1350), Countess of Schauenburg, was a daughter of Count Henry I and his wife, Helwig of Bronckhorst.
It was named after Schauenburg Castle, near Rinteln on the Weser, where the owners started calling themselves Lords (from 1295 Counts) of Schauenburg.
Helvig of Schauenburg (1398–1436), also known as Hedwig of Schauenburg, was a duchess of Schleswig and a countess of Holstein from the family of Schauenburg, and ancestor of the Danish Royal houses of Oldenburg and Schleswig-Holstein-Sonderburg-Glücksburg.
Henry III, Count of Schauenburg-Holstein (d. February 1421 in Bordesholm) was Bishop of Osnabrück as Henry I from 1402 to 1410, and also Count of Holstein-Rendsburg from 1404 until his death.
In a document dated 1100, the two brothers are called of Schauenburg, after a castle which their father had built near Friedrichroda.
Their united forces formed a very respectable array, and they took and destroyed a number of towns, and had recovered a great part of the County of Holstein, when they were opposed by Schauenburg Count Adolf IV of Holstein, who had been joined by his liege lord Albert I, Duke of Saxony and Prince-Archbishop Gerhard II of Bremen.
The castle's foundation was laid about 1068 by the Thuringian count of Schauenburg, Louis the Springer, a relative of the Counts of Rieneck in Franconia.