The Battle of Messines 1917. The prelude to the Battle of Passchendaele and the biggest man-made explosion before the A-bomb.

The Battle of Messines in 1917 began with the detonation of 19 massive underground mines beneath German lines on June 7th, creating the largest man-made explosions in history before the nuclear age and killing thousands of German soldiers instantly. This devastating simultaneous blast, planned meticulously by General Herbert Plumer, preceded a successful infantry assault to capture the strategic Messines Ridge, a key stronghold near Ypres, and served as a precursor to the larger Third Battle of Ypres (Passchendaele).