How long it take to film the longest movie ever many years.?

That movie would be “The Great Patriotic War” a Moskfilm production of the Napoleanic War, from the Russian perspective. It took years to make, and used (literally) thousands and thousands of “extras” to replicate the battle scenes. Also they replicated Czar Nicholas’ palace, and grand ballroom, as well as other extremely large and complicated sets. If you ever get a chance to see this film…do so! There is a scene of the opening of the battle of Borodino which commences with a view of soldiers, cavalry, cannon emplacements etc. etc. As the battle begins the camera pulls back, and pulls back, and pulls back…and you observe literally thousands of soldiers fighting, cannon emplacements, cavalry units, etc…over a view of many miles! Moskfilm duplicated the battle with a full compliment of actors and extras…literally regiment upon regiment…it is the most impressive battle scene ever structured and filmed. The included painting of eh battle will give you some idea of the size and scope. Needless to say, under the Soviet Government, a film of this nature could be made and costed, as it represented the heroic Russian people defeating Napoleons armies, rather like our own commemoratives of our revolutionary war.