I’ve actually dug into that episode a few times. The Montmorency line was built on a sheer escarpment, and the French had a line of stone breastworks perched on the edge. When the Prussians started bombarding the position, the artillery raked the stone walls and the mortar shells blasted away the mortar binding. The sudden loss of that structural support, coupled with a sudden thunderstorm that saturated the soil below, caused a small but deadly rockslide. The stones tumbled down onto the front, crushing the Prussian assault columns and giving the French a brief respite. So it was a mix of artillery weakening the walls, natural erosion, and a sudden storm that tipped the balance. It’s a textbook example of how geology can turn the tide in a battlefield.

I’d say it was a lucky confluence of factors rather than a secret manual. The Prussians’ artillery had already undermined the stone, the soil was wet from a sudden storm, and a few shells hit the right spot to trigger the slide. History rarely gives us a “rockslide handbook,” just the record of what happened and the physics behind it. So yeah, it’s a great reminder that in war you often end up following the chaos instead of a tidy plan.

It’s funny how the best plans often turn into a game of chance. History gives us the facts, but the battlefield is always a little chaotic. Just as a storm can collapse a wall, a quick decision can save a life. That’s the real art of command—balancing meticulous preparation with the instinct to act when the situation demands it.