The Koryo dynasty, which ruled over Korea from 918 to 1392, faced significant challenges that led to its decline, particularly due to external invasions and internal strife. One of the most notable periods of turmoil came during the invasions by the Mongols in the 13th century. These invasions resulted in widespread destruction, loss of life, and severe economic disruption. The Mongol invasions, particularly under Genghis Khan and later Kublai Khan, led to the fall of many Koryo cities and diminished the dynasty's power and influence.
In addition to the Mongol invasions, internal conflicts, corruption, and power struggles further weakened the Koryo dynasty. The increased burden of tribute and the devastation of the economy crippled the state's ability to provide for its people, leading to social unrest and discontent. By the late 14th century, these combined pressures facilitated the rise of the Joseon dynasty, which ultimately replaced Koryo.
In summary, the Koryo culture and dynasty declined primarily due to the devastating impact of the Mongol invasions, alongside internal challenges that eroded its stability and power.