뉴스레터

In September 668, Koguryo's Pyongyang Castle fell. The ancient Korean kingdom had been swept up in internal turmoil since the death of the great general Yeon Gaesomun and could no longer withstand the fierce attacks by the Silla-Tang allied forces. Major areas had already surrendered or fallen to Silla and the Tang dynasty. Some forces of resistance remained and there was a series of movements to revive Koguryo, but they were not enough to rebuild a fallen kingdom. After lasting for more than seven hundred years, that kingdom disappeared into history.

Major Wars and the Centralization of Power

In terms of Koguryo history, the beginning of major wars in East Asia was the war it fought with the Sui dynasty. In particular, the Sui dynasty's second invasion of Koguryo in 612 was the most massive war thus far between the two. For that war alone, it is said that the Sui dynasty mobilized more than 1.13 million troops. Through the multiple conflicts the Tang dynasty experienced with Koguyro, it also mobilized hundreds and thousands of troops. The number of professional soldiers were not enough to form such large armies, so the Tang dynasty requisitioned its garrison militia called fubing (府兵) as well as countless farmers. To raise the massive amount of fiscal resources required to go to war, the Tang dynasty also had to establish a stable taxation system and organize bureaucrats to effectively collect taxes. Evidence of such preparations can be glimpsed from revisions made to the legal codes of the Sui and Tang dynasties which managed to centralize their state systems.

To stand up to such massive Sui and Tang forces, Koguryo too had to requisition hundreds and thousands of men. It had to deploy not only standby troops from the five tribes, but locals from castles in non-central regions as well to defend the kingdom. A considerable amount of fiscal resources was put into securing provisions and repairing fortresses or weapons. These measures hint that Koguryo also felt the need to further centralize its own state system. And such a need explains the temporary stabilization of Koguryo's royal authority between the late sixth and early seventh century or Yeon Gaesomun's coup d'état in 642 and his family's autocracy thereafter.

The major wars Koguryo fought against the Sui and Tang dynasties ended up reinforcing the centralization of each country's state system. Of course, it wasn't the first time for a centralized state system to emerge. Reflecting upon the experiences of the Jin and Han dynasties, the Sui and Tang dynasties organized their state systems to correspond to those from the period of the Northern and Southern dynasties. Beyond the third and fourth century, Koguryo centralized its state system that used to be a five-tribe federation. The new law proclaimed in 372 was indicative of such a state system centralization. Yet, compared to the centralizations previously carried out in the fifth and sixth centuries, the state system of various East Asian countries in the seventh century tended to exhibit an even greater degree of centralization.

Major Wars and the Development of Transportation Routes

To invade Koguryo, the factor the Sui and Tang dynasties had been concerned about the most was the transport of military supplies. In 645, Emperor Taizong of Tang even confessed of the difficulties in trying to attack Koguryo by saying "the Liaoshui River north of Youzhou is nearly 2,000 lis away, but there are no prefectures or commanderies in between to provide supplies and provisions to troops on the move." Until the mid-seventh century, the range of the Sui and Tang dynasties' administrative rule reached only as far as Youzhou to the north, which is today's Beijing area.

Of course, their forces did reach up to Liaoxi, but to the north of Youzhou, only units such as zongguanfu (總管府), had been installed and operated for military rule. And the few prefectures and counties that were installed remained underdeveloped. The inhabitancy of the Han Chinese was restricted while native nomadic, hunting tribes were spread out. Garrisons like zhen (鎭) or shu (戍) managed by a zongguanfu were scattered here and there to stabilize the frontier and support trade. Therefore, it was challenging to procure military supplies necessary for major wars all the way to Liaoxi.

The Sui dynasty already faced a crisis through its first clash with Koguryo in 598. When Koguryo's King Yeongyang attacked the Ying zongguanfu in Liaoxi, Emperor Wen of Sui set out on a massive counterattack by mobilizing armed and naval forces that amounted to 300,000 troops. However, the monsoon season delayed the military procurement, which left the Sui army stranded in Liaoxi where most of the troops died of starvation or disease. Meanwhile, the Sui naval forces ran into a typhoon that led them astray, causing them to eventually drown. Routes via land and sea had both proved to be defective for the Sui dynasty.

Emperor Yang of Sui made efforts to fix such defects as he planned to attack Koguryo. One such effort was the Yongji Canal's construction that began in 608 to connect Luoyang and Zhuojun. Prior to this, the transportation route between Changan and Luoyang was repaired and supplies from Jiangnan were channeled to Luoyang. These measures were aimed at allowing supplies from Jiangnan to be transported all the way to Zhuojun. And from Zhuojun to Liaoxi, war supplies would be transported by draftees called minfu (民夫).

In addition, ships to transport the Sui naval forces were built. An extensive shipyard was constructed in the Shandong area where more than 300 large vessels were built. The Sui dynasty also sought to secure a shipping route that connected the Miaodao Archipelago, the Liaodong Peninsula, and the Daedong River to be able to transport military supplies. By the war in 612, the row of Sui vessels lined up with their stern and bow touching one another is purported to have stretched out for hundreds of li.

Repairing land and sea routes was therefore what made it possible for the Sui dynasty to mobilize 1.13 million troops to attack Koguryo in 612. Yet, the aforementioned remark by Emperor Taizong of Tang in 645 indicates that it was still difficult to see drastic improvements made to transportation circumstances. Shipbuilding in the Shandong area destroyed its forest and caused massive flooding. This led to the outbreak of a revolt in the area. Revolts also broke out in other areas due to mobilization for war and repairing transportation routes.

Despite such problems, the condition of land and sea routes in East Asia was gradually improved during the seventh century. In 648, the Tang dynasty built a massive vessel at Jiannan, today’s Sichuan province, and had it shipped to the Shandong area. Although people continued to suffer from being mobilized for such projects, transportations routes running from north to south and east to west in central China were developed and transportation facilities between Northeast Asia and the northern parts of Inner Asia generally became repaired. These developments later became the source for publications dealing with historical geography such as Huanghua sidaji, Record of the Imperial Glory Reaching Out in Four Directions, by Jia Dan (賈耽, 730-805).

Transportation developments also occurred in other Northeast Asian areas. The Korean kingdoms Silla and Baekje increasingly used sea routes to engage in negotiations with the Sui and Tang dynasties. As wars intensified between the three kingdoms on the Korean peninsula, inland and water transportation routes became developed within each kingdom’s territory. Proof of this was recently discovered in a mountain in the Okcheon area, which turned out to be a road the kingdom of Silla had developed for military purposes in the seventh century.

Transportation routes were indeed vital to ancient societies. They were necessary to be able to transport human and material resources, thereby allowing a central government to effectively rule areas beyond the capital. And water routes were particularly efficient for transportation. That is most likely why states and civilizations prospered around major water sources such as the Songhua River, Amnok River, Daedong River, Han River, and Nakdong River. And beyond the fourth century, sea routes began to emerge in Northeast Asia. Between the third and fourth century, Koguryo conquered Seoanpyeong at the mouth of Amnok River and advanced into the broader East Asian scene through the Yellow Sea. Baekje and Silla also crossed the Yellow Sea to establish international relations. In other words, marine transportation across the Yellow Sea was what prompted the three ancient Korean kingdoms to accept East Asian cultures and reorganize their own state systems.

Based on the developments covered above, major wars and the improvement of transportation infrastructures during the seventh century are likely to have contributed considerably to enabling East Asian countries to actively exchange with one another based on centralized state systems. Improved transportation conditions allowed cultures to be more quickly adopted and transformed to better suit each area’s reality. This may be linked to the process through which Silla, Balhae, and Japan adopted and transformed systems of the Tang dynasty. Hence, major wars in the seventh century resulted in forming a more closely-knit cultural network in East Asia.