e founding king strengthened relationships with them through a host of marriages with daughters of local clans.
Wang also embraced refugees from Balhae. Such an approach offered legitimacy to the Goryeo Dynasty, which enabled Wang's descendants to establish the infrastructure of a Confucian state.
The Ten Injunctions named Buddhism as the state religion, but also insisted on the study of the Confucian classics. While Buddhism exerted great influence on Goryeo, as far as the political system was concerned, the country was built and operated under a strict Confucian model involving civil service exams, Confucian bureaucratic systems and even had a national Confucian academy called Gukjagam.
Understandably, the anti-Khitan policy angered the Liao Dynasty, which invaded Goryeo three times at the dawn of the second millennium, but Goryeo overwhelmed their enemy, finally defeating them and causing them to surrender.
The most outstanding war hero from this period was General Gang Gam-chan who, ordered the destruction of a makeshift dam in order to sweep away the Khitans who were midway across a river.
In recognition of his feats, the Korean Navy named a destroyer after him in 2006.
Under a Confucian-based political system, Goryeo overtly favored civilian bureaucrats over army officials whose time-honored complaints eventually erupted in 1170.
A group of army officials succeeded with a rebellion to start a military dictatorship whose commanders were replaced three times in bloody activities in less than two decades before Choi Chung-heon took power in 1197.
Over the next 60 years, Choi and his offspring controlled the country under a few nominal kings until 1258 when the military dictatorship finished after the death of Choi's grand grandson.
Amid the Choi family's reign, the Mongols attacked Goryeo, which withstood invasions for almost 30 years by even moving its capital to the western island of Ganghwa, before it finally sued for peace in 1259.
In return, Goryeo had to endure a series of humiliating measures including the downgrade of Goryeo monarchs' titles and the forced marriage of Goryeo princes with princesses of the Mongolian Yuan Dynasty.
With Mongol troops stationed at the capital of Goryeo, Yuan actively engaged in the politics of the Korean Peninsula.
Goryeo managed to survive this difficult period and regained its sovereignty midway through the 14th century when Yuan faded away so as to carry out a series of reformative policies.
However, its national prowess had weakened too much under the century-long Mongolian influence to regain its past glory and it met its end in 1392 at the hands of one of its own generals, Yi Seong-gye.
Goryeo's Contribution to World Intellectual History
Although the war against Mongols devastated Goryeo, it also led to a period of great cultural production. The most significant cultural asset produced was the carving of the Buddhist texts known as the Tripitaka Koreana, which people believed would protect them from Mongol invasions.
The importance of the Tripitaka Koreana cannot be over-emphasized: it is the world's most comprehensive and oldest intact version of the entire Buddhist scriptures and it is written in Chinese characters comprising more than 52 million individual characters, without any known typos.
The scriptures are carved onto more than 80,000 wooden printing blocks and are held in the magnificent Haeinsa Temple in southern Korea where they remain in an almost perfect state despite no high-tech storage devices after several centuries.
They are designated as the National Treasure No. 32 of Korea, and Haeinsa Temple's facilities, which hold them, are UNESCO World Heritage sites.
With regards to printing, Goryeo was definitely advanced, more than Europe at that time. On top of the Tripitaka Koreana, which was carved onto wooden blocks, the medieval state came up with the technology of moveable metal print.
Historical records note that Goryeo printed its first book based on this innovative method in 1234, but the oldest extant book printed with this technology is Jikji (a Buddhis