Sansho the Bailiff (1954)

This reminds me in mood of The Bicycle Thief or Umberto D - life is hard and people treat each other like shit.

The setting here is 11th century Japan, where a local nobleman is exiled for defying the military and helping the peasants. Before leaving, he tells his young son to remember mercy for others is the most important quality in a person.

His wife and children are eventually kidnapped, separated and sold into prostitution and slavery, respectively. Ten years pass, with the mother trying to escape continually; eventually her captors cut the tendon in her foot, hobbling her. The brother and sister grow up in slavery, and the brother forgets his father's lessons on mercy. But one day he and his sister are breaking branches in the forest, and the action is identical to their actions the night before their kidnapping. The son remembers his father and starts to change.

This movie is a classic by Kenji Mizoguchi, and it will grip you. By the end I was hating humanity, particularly since there are still slaves in the world. It seems like we've learned nothing. But the movie is wonderful.