Originally Posted by magnik
TRHH William and Harry
HRH Prince Charles and Lady Diana Spencer
HRH Prince George (born as HH) and Lady Elizabeth
HM Carl XVI Gustav and Silvia
These marriages are not between royal houses. (I'm not sure why you mention Princes William and Harry at all, since at the time of your post neither one was married, and Prince William has since married a commoner):
- Lady Diana Spencer was not a royal highness before (or after) her marriage to Prince Charles.
- Prince Albert (who later reigned as George VI) was
born a prince of a royal house but married someone who was not
of royal birth but rather the daughter of a Scottish Earl. In fact, the Queen Mother (as she was later known) had many had many commoners in her lineage.
- The current Queen of Sweden was born Silvia Sommerlath and most definitely a commoner.