Yi led his ships in pursuit, only to be struck by a musket round in the armpit. His last words were instructions to keep on banging his battle drum so that his fleet would not realize he had died until the battle was won. Eight days after the calamitous sea battle, Japanese forces completed their evacuation from the Korean peninsula.

The hwacha’s archaic-seeming configuration of rocket-powered missiles stacked one row upon the other would be echoed centuries later in several World War II-era designs such as the truck-mounted Soviet Katyusha rocket and the American Calliope, which stacked 60 4.5-inch rockets in tubes on a Sherman tank. Today rocket launchers remain a terrifying form of artillery, able to saturate a target with explosive rockets that all impact on the target within a matter of seconds of each other.

The Korean research and development effort behind the hwachastemmed from a conviction that rocket technology could protect the small peninsula from external invaders. However, technological edges must be maintained if they are to endure.

Three hundred years after the Imjin wars, Korean “fire arrows” proved ineffective in battle against a grounded American ironclad. Today, both Pyongyang and Seoul are again investing in advanced missile technology in the hopes it will deter foreign attack.

This article first appeared in WarIsBoring here.

Image: Reuters