This is the third of a 10-part series on Korean history from its mythological, ancient beginning until the present day. This project is sponsored by several companies and public agencies including Merck Korea, eBay Korea, Daewoo Securities and Korea Post. ― ED.

By Kim Tae-gyu and Kevin N. Cawley

The historic era involving the Three Kingdoms, which were located on the Korean Peninsula and a significant part of Manchuria, finished dramatically as the once smallest kingdom, Silla, defeated its two bigger rivals to establish the first-ever unified kingdom on the peninsula.

Along the way, Silla asked for the help of Chinese military forces from the Tang Dynasty, and while helpful at first, this actually led to serious trouble when Tang eventually revealed its intention to take over the peninsula for itself.

Silla managed to drive away the Chinese military power from the old Baekjae and Silla areas but could not do so in the extensive northern territory of Goguryeo.

Hence, Silla failed to unify the entire expansive northern region with the rest of the peninsula. The Tang Dynasty had its subordinate tribes control what had previously been Goguryeo.

But this did not last for long because refugees from Goguryeo, led by General Dae Jo-yeong set up a new country there called Balhae in 698, which became very prosperous.



The unified Silla and Balhae ruled the Korean Peninsula and Manchuria for about 250 years from the late 7th century to the early 9th century and historians call this the ''Southern-and-Northern States'' era.

The situation was somewhat like the current situation where North Korea rules the northern part of the peninsula while South Korea controls the southern part below the 38th Parallel.

However, the size of the territories under control was much larger a millennium ago during the South-North state period than today where Manchuria is governed by China although many ethnic Koreans still reside there.

Struggles against Chinese forces

The Tang Dynasty had been of great military assistance to Silla helping it defeat Goguryeo and Baekje. After the downfall of the two countries, however, it made no secret of its intention to assume their domains and even attempted to incorporate Silla under its rule.

Silla then fought against Tang for the next decade and obtained victory after beating the latter's army at a castle close to today's Seoul, and then overpowering its navy in the western coast adjoining the Yellow Sea in the mid 670s.



In 676, eight years after the fall of Goguryeo and 16 years after that of Baekje, Silla finally expelled the Tang forces to complete the unification of the Three Kingdoms, which lasted for some seven centuries.

In the process, Silla combined forces with the people of Baekje and Goguryeo.

The long unification campaign was spearheaded by two heroes: Kim Chun-chu and General Kim Yu-sin.

The former became the 29th monarch of Silla, and was renamed King Taejong Muyeol. He ruled from 654 through 661 and played a pivotal role in allying with the Tang forces for the collapse of Baekje. At that time, General Kim Yu-sin headed the army of Silla.

The two Kim's were not relatives, but they were childhood friends and General Kim's sister married the king who was credited with having started the unification initiative.

General Kim helped the son of his brother-in-law, the 30th monarch King Munmu, destroy Goguryeo in 668 and wrap up unification in 676 by expelling the Tang forces.

In return, General Kim was presented with handsome rewards: while alive, he received an honorable title of second-in-chief, next only to King Munmu, and after his death, he was bestowed an honorable king title.

King Munmu is also famous for his patriotism. On his deathbed, the first ruler of the unified kingdom asked to be cremated and to have his ashes scattered in the East Sea in order to become a dragon so that he could defend his country from foreign invasions.

In accordance with his wishes, the ashes of King Munmu were scattered from a small rocky islet, dubbed Daewangam, or "the rock of the great king," approximately 100 meters off Korea's southeastern coast.

Prince of seas

The most respected army leader in the history of Silla would be unarguably General Kim and his equivalent in the navy would be Jang Bo-go, who dominated the Yellow Sea in the late United Silla period.

Jang became a military official in Tang thanks to his mastery of martial arts and horsemanship as well as weapons such as spears, which earned him an official military post.

He returned to Silla in the early 9th century, and with the approval of the king, set up a maritime garrison on an island off the southwestern tip of Korea, which dominated the Yellow Sea for decades, and protected Silla merchants from pirates.

His power as a maritime figure grew so much that he even became involved in politics and was appointed prime minister. However, he was later assassinated by the Silla royal family.

The fortune of Unified Silla waned as power struggles such as the one involving Jang continued in the 9th and early 10th century when military kings killed one another as well as their relatives in a bid to control the peninsula.

Many of them sought only pleasure at the expense of the lives of the people even when the country's sustainability was questioned due to political turmoil and peasant revolts, typical signs of a decaying nation.

Silla was finally brought to an end in 936 when its final king offered the 1,000-year-old rule to the newly emerging Goryeo.

But Unified Silla played a key role in regards to cultural, intellectual and religious perspectives. Through exchanges with the Tang Dynasty it managed to introduce advanced Chinese culture to Silla and also to Japan.

Silla boosted both Buddhism and Confucianism and some of its Buddhist monks traveled to China and even to India to study.

Woodblock printings from this period are famous and an ancient print of a Buddhist sutra written in the 8th century was found at one of its pagoda towers located in its capital, the oldest discovered printed material in the world.

Dr. Kevin N. Cawley is currently the Director of the Irish Institute of Korean Studies at University College Cork (UCC), Ireland ― the only institute in Ireland dedicated to promoting Korean studies ― funded by the Academy of Korean Studies, South Korea. He was previously a Gyujanggak Fellow at Seoul National University.

In detail Unified Silla (AD668-935): Korea's first unified country after the Three Kingdom era Balhae (AD698-926): A Manchurian kingdom set up after the collapse of Goguryeo Goguryeo (BC37-AD668): An ancient Korean kingdom in the northern Korean Peninsula and Manchuria Baekje (BC18-AD660): An ancient kingdom in southwest Korea Silla (BC57-AD935): An ancient kingdom in southeast Korea Tang Dynasty (AD618-907): An imperial dynasty of China, which flourished in terms of cultural capacity and military power Kim Chun-chu (King Muyeol, 602-661, reign 654-661): Silla's final monarch before unification, who attracted the Chinese forces so as to eventually achieve unification King Munmu (626-681, reign 661-681): Silla's first monarch after unification, son of King Muyeol Kim Yu-sin (595-673): One of the most respected soldiers in Korean history, who greatly helped Silla attain the peninsula's first unification Jang Bo-go(787-846): One of the most powerful maritime figures in Korean history, who effectively ruled the Yellow Sea for decades in the early 9th century East Sea, Yellow Sea: The East Sea is the sea off Korea's eastern coast and otherwise called as Sea of Japan, while the Yellow Sea is located between the Korean peninsula and China. Goryeo (918-1392): A Korean kingdom that succeeded the Southern-and-Northern state period