You've got a massive army at your disposal, but people need to see its size, not only to show off your power, but to hurt morale of anyone who stands against you. So you have them march, either in a straight line that takes all day, or massive formations that cover even the largest fields. Of course, The Empire can be expected to show this off.
Of course it's important that they actually fight well, and many Evil Overlords heed that advice, while the logistics of providing food and toilet facilities for such a huge army are usually ignored or Hand Waved. Also, doesn't work if the heroes are using a bottleneck, like a narrow bridge. Or, god forbid, a thin path between the mountain and the sea... In fact it's surprising how often this trope goes south.
Truth in Television, going back to most ancient armies.
Compare Flaunting Your Fleets.
Contrast Suspiciously Small Army.
- Saruman's army in The Two Towers.
- And Sauron's outside the gates of Minas Tirith in The Return of the King.
- Happens at least once in each of the Star Wars Prequels.
- In The Phantom Menace, where battle droids are marching in formation on the Trade Federation Control Ship shortly after the movie begins, and later as they march into battle outside the city on the planet near the film's climax.
- In one of the last scenes of Attack of the Clones, where the clone army is shown marching in formation on Coruscant as they depart for war.
- In Revenge of the Sith, where a battalion of clone troopers marches into the Jedi Temple, led by Darth Vader.
- Also happens in The Empire Strikes Back with Death Squadron and in Return of the Jedi when the Imperials greet Palpatine.
- The hyenas in The Lion King, which references...
- Pretty much the entire point of Triumph of the Will.
- The ant army in Antz.
- The Qin army in Hero.
- Here is a nice example (Napoleonic troops entering Russian territory; ends around 2:20).
- Done in Ilya Muromets. It actually has a world record for extras.
- In the teaser for Kung Pow! Enter the Fist's sequel, a massive army charges over a hillside... and the Chosen One just stands there trying count how many's coming at him.
- The Imperial Order in the later Sword of Truth books fields an army that numbers in the millions. To put this in perspective, before they showed up, 100,000 troops was considered a large army.
- In Ayn Rand's We The Living, one of the new Communist movies consists entirely of this.
- In The Silmarillion, at the Great Battle of the War of Wrath, Morgoth's army of Orcs, Trolls and Balrogs has grown so large that it fills the entire plain on which the previous battles were fought.
- In The Wheel of Time The Dragon Reborn has armies numbering in the hundreds of thousands. In The Path Of Daggers, one character thinks to himself that he can remember when 5000 men was a large army, before the coming of the Dragon. Several scenes describe the tiresome logistics of marching and supply, though that gets (much) easier with the advent of Mass Teleportation.
- However, military parades are given very little attention in the series.
- Jesus' army of saints at the Battle of Armageddon in the Left Behind book Glorious Appearing. Of course, they're mostly there to praise the Lord while Jesus does all the work of slaying His enemies with the Word Of God.
- Jamie Hewlett's music video Monkey Bee is a remix of a song from his Monkey: Journey To The West album. As expected, it is loosely based on Journey to the West. At the end of the video, the Monkey King is faced with a massive amry of the undead, resulting in a Bolivian Army Ending. The video can be seen here.
- The Chronicles of Narnia video game battle sequences featured endless swarms of enemies marching past in the background. The developers actually wrote a software app called Battlemarch to produce the effect.
- This trope is invoked by the Sligs for an animation test for the canceled Oddworld game, Hand of Odd. Done infront of a picture of a burger.
- Invoked in cutscenes of Rise of Legends by both Giacomo and the Doge of Venucci. Clockwork spiders and mechanical soldiers, bonus.
- Done at the beginning Gears of War 2, complete with an inspiring speech.
- It's not actually an entire army, but when the US task force tries to arrest Occelot in Prague in Metal Gear Solid 4, it takes over three minutes for the several dozens of trucks, ten patrol boats, six helicopters, and hundreds of soldiers to come out of their hiding spots and surround his boat on the river. But even with just three mooks and himself, Ocelot doesn't think about surrendering. But in a terrible subversion, he already got the master password to shut down all their equipment and when the soldiers are ordered to open fire, nothing happens. Then Ocelots mooks start mowing down the entire Task Force in a few moments.
- Animaniacs had one of these. Episode: 'King Yakko', a thinly disguised parody of Duck Soup with Yakko in the Groucho Marx role. He and his siblings search for the invading army, until it's pointed out. Yakko ends up seeing one of these. He figures it'd take a commercial break to come up with a viable battle plan.
- ReBoot's pilot episode has Megabyte's mooks marching across the underground lair. They aren't going anywhere, but it looks awesome and is only meant to intimidate Bob.
- Military Parades, most famously, the Red Army. China, India and Russia continue to mount the largest military parades in the world.
- Particularly Napoleonic French army doctrine, since other armies formed into lines to maximise firepower. When your three man deep line saw a mass of men in column marching relentlessly at you, and nothing you could do with your volleys would seem to do more than dent the outer edges of that gigantic column, it would understandably flee. Only the British seemed immune to this effect, if only because they were more scared of their sergeants and brutal discipline than of the columns of doom.
- James Oglethorpe used a forest that hid where his army had come from and where it was going, and marched a small army in a circle to make it look much bigger.
- Rommel succeeded in pulling off the same "unending loop" trick, without the benefit of forest cover and with tanks.
- Improved upon, perhaps by others in the same desert, who used trucks disguised as tanks, tanks disguised as trucks, the truck and tank disguises left behind in the front line where they would be seen, trucks pulling trailers that left the tracks of tanks, fake airfields with fake aircraft (sometimes bombed with fake bombs), fake railroads and railheads 100 miles south of the real railheads, ammo, water and fuel dumps that were sometimes fake covering the real ones. All this constructed to a realistic timetable that indicated an attack several weeks later than the actual attack. Job done. Nazis lose.
- The Soviets used this trick with strategic bombers during their military parades in the 1950s, decieving American observers and creating the myth of the Bomber Gap. Believing their long-range bomber fleet to be massively inferior to the Soviet one, the Americans promptly invested as much as they could in research and production of ICBMs. Yes, much of the Cold War arms race was due to this ploy.
- The trick is Older Than Feudalism. Military manuals written in Greece before the birth of Alexander the Great already feature passages detailing how to make your army look bigger than it is. Ploys include the "unending loop" as well as alternating spears to make formations seem twice as wide, marching in single file to make columns stretch endlessly, marching in hollow formations using dust clouds to hide true numbers, and dressing up women as soldiers ("though you should never allow them to throw missiles, for a woman immediately betrays her sex when she tries to throw").
- Victorious Roman generals would be feted with "triumphs", enormous festivals meant to honour the conquering hero of the Republic. An enormous parade would begin at the Field of Mars, winding its way past shrines while crowds of plebeians roared "Io Triomphe!", before finally reaching the great Temple of Jupiter. The general was followed by his soldiers as well as a host of toga-clad senators and priests, families of prominent patricians, and the Vestal Virgins. Chariots bore the plundered loot of subjugated tribes and captured barbarians were yanked along in chains. The general, at the head of the procession, was followed by a slave who held a laurel wreath over his head while whispering "remember, you are mortal" into his ear. Later, during the Empire, only the Emperor was feted in this manner - whether he had led his troops in the field or not.
- The last non-Emperor to get a triumph was Belisarius. Because of course he was a Four-Star Badass.
- The Trooping of the Colour can look suspiciously like this.
- This tactic has also been recorded in The Bible - from an initial standing army of 32,000 men, Gideon selected 300 men and used this tactic against a much larger Midianite-Amalek combined force.