The Koreans are one of the five civilizations featured in the Conquerors expansion. Historically, they were not as powerful compared to the other Far Eastern kingdoms. However, their tacticians, most notably Admiral Yi Sun-Shin, made important contributions in innovating cutting edge weaponry when conditions were especially dire during the Japanese invasions and frequent raids from Wokou pirates. One of their most recognized innovation was the Hwacha which fires a series of small bolt like rockets. This is represented by a Mangonel with higher range granted by the team bonus and the unique technology. Being able to successfully defend itself despite the numerical disadvantages, they are a defensive civilization similar to the Byzantines, but focuses more toward ranged units. As a result of their innovation and knowledge of gunpowder (which originated from China, though the Koreans had to develop it separately since the Chinese would not share their secrets) the Koreans are one of the few civilizations that have two unique units. The Castle-based unique unit is the War Wagon, a horse-drawn carriage that is essentially a heavily armored cavalry archer. The War Wagon fires a bolt similar to the Galleon. While stronger and better armored than the cavalry archers, they are slower and more expensive. The Dock-based unique unit is the Turtle Ship, an armored and spiked ship which is a heavily armored, short-range artillery ship that is effective against Fire Ships and Demolition Ships. The Turtle Ship is slower than many other ships, but makes up for speed in raw power and durability. A single Turtle Ship can take down a small fleet of ships, while a fleet of them can annihilate a large part of an opponent's navy. The Koreans were also fine stone workers, especially in crafting sculptures and pottery whose highly prized ceramic coated celadon glaze was the finest in the world. To reflect their stone artisanship and defensive capabilities, their villagers mine stone faster. Finally, to keep in touch with their defensive theme, their Watch Towers are automatically upgraded to Guard Towers in the Castle Age and Keeps in the Imperial Age.