1 December] 1884 – 22 May 1952) was a Russian Bolshevik revolutionary, notable as one of several men responsible for carrying out the murder of the Romanov family, including the deposed Tsar Nicholas II, his wife, their children, and their retinue.

The most striking event for Ermakov was the expropriation of the factory cash desk in favor of the Ural Committee of the RSDLP, during which 6 people were killed and 12,400 rubles were seized.

By mid-1918, with White Army forces now edging closer to the outskirts of Yekaterinburg, the local Bolshevik authorities were instructed by Yakov Sverdlov, with the assent of Vladimir Lenin by means of a telegram, to execute the imperial family.

According to historians Greg King and Penny Wilson, Ermakov played a leading role in the executions, and is considered to have been the right-hand man of chief executioner Yakov Yurovsky.

After momentarily stopping the firing due to the large amounts of rifle smoke, the executioners were ordered to also execute the Tsar's daughters Grand Duchess Olga, Tatiana, Maria and Anastasia, and their remaining servant Anna Demidova.

According to an account by Peter Voikov, who was the commissar of supplies for the Ural Soviet, during the execution Ermakov yelled out that the maid, Demidova, and the youngest daughter, Anastasia, were still alive.

[6] With the exception of Ermakov, his men were not allowed to participate in the process of stripping, mutilating and disposing of the bodies; they were ordered back to the city as Yurovsky did not trust them and was displeased with their drunkenness.

In 1935, Ermakov, claiming to be dying of cancer, gave an interview to American journalist Richard Halliburton, describing the burning and destruction of the bodies of the Imperial family and their servants.

Since the fall of the Soviet Union, some local Communist Party members annually pay tribute to his gravestone on each anniversary of the murders, though on a few occasions it has also been vandalized.

Ermakov is shown as suffering from PTSD as a result of his involvement in the killing of the family and their retainers, witnessing hallucinations of a bloody Alexei at several points throughout the film.