Charles I of Austria

• 

  
  Charles IV
  (53 stamps, 1918-1919, 49 are ovpts)
  
• 

  
  Karl I
  (28 stamps, 1918, 14 are ovpts)
  
• 

  
  Karl I
  (55 stamps, 1917-1919, 33 are ovpts)
  
• 

  
  Mircea & Karl I
  1913
  
• 
  10h+10h issue=Karl's Fund
  
  Karl I
  (2 stamps, 1918)
  
• 

  
  Emperor Karl I
  (16 stamps, 1917-1918, 11 are ovpts)
  
• 
  2h issue=1918
  
  Emperor Karl I
  (31 stamps, 1918)
  
• 

  
  Emperor Karl I
  (35 stamps, 1917)