Атака мертвецов" (Attack of the Dead Men).

Атака мертвецов" or Attack of the Dead Men, is a film of the war and horror genre produced by the Russian director Sergei Mikhailovich Eisenstein, which represents the combat between Russian and German troops in the town of Osowiec-Twierdza in the early stages of the Brusilov offensive.

It has its parts of true, but also fantasy-horror.

During this battle, the 13th Company of the 226th Regiment found itself heavily damaged by a German attack and bombardment, which resulted in the heroic defense (and a Pyrrhic victory) of the Russian forces.

The victory was a small decisive event in the defenses of East Prussia and West Prussia, it was not decisive in the general war but it was a remarkable event (and a victory for the Brusilov Offensive after all).

The problem was that during the combat between Germans and Russians there were incidents that released a mixture of poison gases and chlorine.

Forcing a hasty evacuation of the civilians present by imperial troops, poorly prepared for the event, while the Germans were not so affected by the incident.

This caused an event (more exaggerated in the film), where the Russians performed important maneuvers that frightened the Germans, due to the bloodied and zombie-like appearance of the Russian combatants after they were bombarded and poisoned by the local incident.

Actually here is the fantasy part, with literally some undead attacking Germans as a last will.

That is why this film falls within the horror genre (both fantasy horror and innate war horror), and is considered the beginning of the zombie genre.