County of Oldenburg

Elevated to Duchy of Oldenburg in 1774

• Ruling Houses
• 

  House of Oldenburg
  1088–1448

• 

  House of Oldenburg-Delmenhorst
  1448–1667

• 

  House of Oldenburg
  1667–1773

• 

  House of Holstein-Gottorp
  Frederick August I
  1773–1774