This is Tsarevich (Prince) Dmitri. Legend has it, that Tsar Boris Godunov had him murdered when he was a seven year old boy so that no remaining heirs to the previous dynasty could usurp his current right to the throne. In the famous Clock Scene in the opera, "Boris Godunov," the Tsar's hallucinations of the dead Tsarevich Prince are triggered by the chiming of the clock.
