And you thought Lord of the Rings was a big production.....

[solicitr]

On the 1970 Italo-Soviet film Waterloo:

Mosfilm contributed more than £4 million of the costs, nearly 16,000 soldiers of the Red Army, a full brigade of Soviet cavalry, and a host of engineers and labourers to prepare the battlefield in the rolling farmland outside Uzhhorod, Ukraine (then part of the Soviet Union).

To recreate the battlefield authentically, the Russians bulldozed away two hills, laid five miles of roads, transplanted 5,000 trees, sowed fields of rye, barley and wildflowers and reconstructed four historic buildings. To create the mud, more than six miles of underground irrigation piping was specially laid.
[...]

Months before the cameras started filming, the 16,000 Red Army soldiers began training to learn 1815 drill and battle formations, as well as the use of sabres, bayonets and handling cannons. A selected 2,000 additional men were also taught to load and fire muskets. This army lived in a large encampment next to the battlefield. Each day after breakfast, they marched to a large wardrobe building, donned their French, British or Prussian uniforms and fifteen minutes later were in position. The soldiers were commanded by officers who took orders from director Sergei Bondarchuk by walkie-talkie. To assist in the direction of this huge, multi-national undertaking, the Russian director had four interpreters permanently at his side: one each for English, Italian, French and Serbo-Croatian.

This included a mass charge by 2,000 cavalry- not one of them CGI.

[sauronsfinger]

This included a mass charge by 2,000 cavalry- not one of them CGI.

Which makes perfect sense given that CGI in films had not yet made its debut.

[Primula Baggins]

I think solicitr's point is that most filmmakers would not be able to afford a real army or a real cavalry charge; such things were usually "cheated" somehow, using narrow shots of a few actors. When those kinds of "cast of thousands" scenes did get filmed, the shots tended to show up over and over again in other films.

[sauronsfinger]

Which is a great reason to be thankful that technology has now evolved to have such great events on film for all to see.

[solicitr]

such things were usually "cheated" somehow, using narrow shots of a few actors.

So did DeLaurentis and the Red Army. After all, Ney actually hurled over four times as many, some 9000 horse, at the Anglo-Dutch line.