Earldom of Northumberland

• Ruling Houses
• 

  House of Percy

• 

  House of Neville
  John Neville

• 

  House of Percy
  Restored

• 

  House of FitzRoy
  George FitzRoy

• 

  House of Seymour
  Algernon Seymour

• 

  House of Smithson-Percy