EDIT: A little background to the question for people saying scouting (and to clarify why I initially posted). This was my first thought as well, but in reading about Roman history, I’d found out that they were notoriously bad at scouting, as it was something that they felt was below them (and it cost them at Lake Trasimene). Thats when I realized I had no idea how these armies would actually find each other
In: Other
Often, they didn’t. They bumped into each other. Not the entire armies, of course. It’s not the Hollywood trope of sunrise (bird song) the hero opens his eyes, blinks as he’s blinded by the early sun, only to find an army of 100,000 arrayed in front of him. But their advanced units would bump into each other very much unexpectedly.
What others wrote here is also correct but not all battles were pitched battles or sieges. Even Gettysburg, barely over 150 years ago, was not planned or expected to take place in Gettysburg. The armies were looking for one another but had moved past one another, unknowingly. By the time they met there, the Union was attacking northwards and westwards from the south and the Confederates were attacking southwards and eastwards from the north.
Seasoned commanders like Napoleon had a good hunch about where the enemy might be, based on scouts and spies. But the scouts took a while to deliver messages and during that time everyone, the enemy and Napoleon, was on the move. Changes in the weather, accidents, new information, meant that an enemy marching north yesterday might be marching west tomorrow. Ultimately, the timing and location of the battle caught both sides by surprise, to some extent.
Latest Answers