It is a montage of clips from the most expensive film ever made (in today's dollars the budget would be over $700 million). The movie is Sergei Bondarchuk's War & Peace, made in Russia in the mid-60's, and these scenes are from the Battle of Borodino, an hour long battle sequence. These were the days before CG animation, there are no special effects creating these huge armies, it is all REAL. 120,000 soldiers in period costumes, thousands of horses, etc. No film will ever come close to this in terms of spectacle, without being, essentially, a work of animation (like The Return of the King). To read more, the address is:
By the way, this video absolutely DOES NOT represent the full effect of the film. Only a big screen can do War and Peace justice. There are a ton of details in the background that can't even be made out on YouTube, and the detail of the final shot in the video (possibly the most epic shot in film history) is completely lost on YouTube.
Doctor: I know it's an embarrassing question, even between husbands and wives, but what do you believe in? Philip E. Marlow: Malthusianism. Doctor: Come again? Philip E. Marlow: Malthus, but mandatory. Compulsory depopulation by infanticide, suicide, genocide or whatever other means suggest themselves. AIDS, for example, that'll do. Why should queers be so special? Doctor: I see. Philip E. Marlow: I also believe in cigarettes, cholesterol, alcohol, carbon monoxide, masturbation, the Arts Council, nuclear weapons, the Daily Telegraph, and not properly labeling fatal poisons, but above all else, most of all, I believe in the one thing that can come out of people's mouths: vomit.