In the 16th century a little-known naval genius helped fend-off a Japanese conquest by use of a unique and effective weapon of war: the Turtle Ship!
In the last decade of the 16th century, the ambitious and capable warlord of Japan,Toyotomi Hideyoshi conceived a plan to invade Ming China, a doddering empire; and to place the Japanese Mikado upon the Celestial Throne in Beijing. As a springboard to this, Hideyoshi planned to first conquer Korea; which stood between the two powers and acted as a stepping-stone.
The Japanese invasions of Korea (1592–98) were extremely well prepared, enormous undertakings. In two waves, 300,000 fierce, battle-hardened Samurai warriors and supporting foot soldiers (Ashigaru) crossed the intervening Tsushima Strait and fought their way up the Korean peninsula. Initially the Japanese made great progress, defeating the Korean defenders at every encounter.
The Japanese had three advantages in this war. First, their Samurai were among history’s greatest warriors. Superbly trained and disciplined, they were possessed of an indomitable fighting spirit that knew no surrender. They wielded matchless swords and other bladed weapons, of a quality and cutting-power never equaled. Both on foot and as cavalry, man-for-man the Samurai had no equal. The second advantage Hideyoshi’s forces enjoyed was the widespread use (and expertise with) the matchlock arquebus. These had come into use in Japan through contact with the Portuguese; and during the last decades of the Sengoku Period had become a decisive weapon on the battlefield. The final advantage the Japanese armies enjoyed was the vast experience in war gained by a century of civil war: the Japanese troops were all veterans of numerous campaigns and battles; whose tactics were battle tested.
To counter this, the Korean defenders had a decisive weapon of their own: the Turtle Ship!
Developed and deployed by Korea’s brilliant admiral, Yi Sun-sin, the Turtle Ship (known among the Koreans as Geobukseon) was a coastal defense galley; but one possessed of some unique features. First, it was a ship whose sides and deck were covered-over; to protect the crew from missile bombardment. The roof, shaped vaguely like the shell of a turtle, was also covered with spikes to counter the Japanese’s favorite naval tactic: to board and clear enemy ships with their ferocious Samurai. It is also possible (though disputed) that the Turtle Ships were plated with iron, hexagonal plates; at least on the roof. The earliest (contemporary) accounts, including Admiral Yi’s own documents, don’t mention iron plating. However, if they indeed did possess metal armor it would make them history’s first “iron clad” warship.
These were not perfect warships, however…