A really, really long 1976 film by
Bernardo Bertolucci starring
Robert De Niro and
Gerard Depardieu, with a small
Burt Lancaster role. The American edition is 245 minutes, and there's a director's cut that's 311 minutes.
The plot covers the lives of two men born around 1900 on the same estate, and in 4+ hours, Bertolucci is able to cover a lot. Depardieu's character is born to a peasant family working on the estate, and DeNiro's is born to the owner of the estate. IMDB says that it covers their lives through the rise of communism, facism, and World War II, but knowing there were still several hours to go, I just wasn't able to get much beyond their childhoods on the estate.