Who married Otto IV of Schaumburg?

Otto IV of Schaumburg (1517 – 21 December 1576) was a German nobleman. He was a ruling Count of Schauenburg and of Holstein-Pinneberg. He was a son of Jobst I and his wife Mary of Nassau-Siegen, a daughter of Count John V of Nassau-Siegen.

He adopted the teachings of Martin Luther. 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. In 1559 he officially began the Reformation in Schauenburg and Holstein-Pinneberg. These areas remained Lutheran throughout the Counter-Reformation and into modern times.

Elisabeth Ursula von Braunschweig-Lüneburg (* 1539; † 3. September 1586 in Detmold) war eine Tochter des Herzogs Ernst I. von Braunschweig-Lüneburg und dessen Frau Sophie von Mecklenburg-Schwerin. Als Ehefrau Ottos IV. wurde sie Gräfin von Schaumburg.