Boris Godunov.

The action takes place in Russia and Poland in 1598-1605. After the death of the feeble-minded Tsar Fyodor Ioannovich, Boris Godunov ascends to the Moscow throne by the decision of the Zemsky Sobor. Boris Godunov, who had gained great influence and power at court during the reign of Ivan the Terrible through intrigue, alliances, and arranging his sister Irina's marriage to Tsarevich Fyodor, had already gained significant influence during the reign of Ivan the Terrible. However, a new pretender to the throne suddenly appears: someone claiming to be the younger son of Ivan the Terrible, Tsarevich Dmitry, who was officially killed in Uglich in 1591.