Earldom of Cornwall

• Ruling Houses
• 

  House of Penthièvre

• 

  House of Conteville

• 

  House of Dunstanville
  Reginald de Dunstanville

• 

  House of Cornwall

• 

  House of Gaveston
  Piers Gaveston

• 

  House of Plantagenet
  John of Eltham