This flag is derived from the royal flag of the last kings of the Árpád dynasty, the first dynasty which ruled the medieval Hungary. For more informations see en:Árpád House Flag.
As a modern political flag, it is also  the semi-official symbol of a Hungarian christian nationalist party, the JOBBIK Magyarországért Mozgalom (Movement for a BETTER Hungary), founded in 2003. The flag is often borne also by the right-wing radical backers of the conservative parties in Hungary.
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