The history of parhae(발해:渤海, Chinese:Po-hai), which had existed from 698 to 926 in the northern part of the Korean Peninsula and the region of Manchuria, has been studied principally in connection with Japan, China and Russia and in Korea. Although especially in Korea, China and Russia, historians are increasingly interested in the history of parhae, they have different positions to and express opinions of it, because the contemporary histories of these countries include parts of the old territory of parhae. For example, while historians in Korea tend to treat the history of parhae as a part of Korean history, Chinese historians tend to treat it as a local history of China. On the other hand, Russian historians have interpreted parhae as an independent state of Malgal(말갈:靺鞨, Chinese:Mohe) which escaped the control of Chinese Government. Similarly, during the period of Japanese control Manchuria, Japanese historians viewed the history of parhae as a part of the history of Manchuria separated from that of China.
In this article I examined certain important issues of the history of parhae, crucial ones by most historians in the examination of parhae---the nationality of its founder, the relation between parhae and Silla, the connection of the people of parhae with those of Koryo (고려: 高麗) after the collapse of parhae. I tried to make it clear that the founder of parhae, Tae Cho-yong(대조영:大祚榮), came from the region of the Sungari River in Koguryo(고구려:高句麗), and the group of people led to the foundation of parhae state were descenedants of Koguryo, by looking into the historical backgrounds in which parhae and Silla(신라: 新羅) were negotiated and conflicted with each other, and by examing suggest the meaning of the Period of Southern and Northern Countries(Nambukguk남북국:南北國) in view of the relation between Khitan which partly succeeded to parhae, and Koryo which replaced Silla.
In the study of the history of parhae, the most difficult problem is the lack of historical materials. The history of parhae must be written, not based upon records left by descendents of parhae, but upon the material of Silla, T'ang, Khitan, Japan and so on. Consequently, for the reconstruction of the history of parhae, it is essential to criticize thoroughly the materials. In this respect, I tried to re-interpret the materials written, for example, from the viewpoint of Chinese.
In Korean history, the period of between parhae and Silla is called that of Southern and Northern countries. The reason for this is that, instead of three Kingdoms of Koguryo, Paekche(백제:百濟) and Silla in the preceding period, two Kingdoms of parhae and Silla formed the main stream of Korean histroy. In fact, as the name with which Silla called parhae, the term 'Northern country' is now used only among Korean historians. But if looking from this point of view, the conception is questionable because the 'Unified Silla' which unfied the Three Kindoms including Koguryo stood together with parhae. For this statement is a contradiction that the Unified Silla incorporating Koguryo and parhae succeeding to Koguryo stood together side by side. Therefore, I distinguished the Unified Silla before the foundation of parhae from Silla after it, and used the term the 'Unified Silla' for only the former.
The greatest mystery of parhae is the issue of Malgal. Were the ruling class who founded parhae were the people of the ruined Koguryo or Malgal entirely different ethinc groups? This is a very important issue because it will also affect on the existing view that, in the racial composition of parhae, the ruling class were the people of the ruined Koguryo and the ruled class Malgal were entirely different ethnically from the former. If two groups were so different, how could they have lived together as constituting people of a nation during the two hundred year period, and how could they have accomplished the changing of the capital four times, without the absolute help of the ruled class?
The records about Malgal(말갈:靺鞨) include the areas of Suksin(숙 신:肅愼) or Upnu(읍루:읍婁) known as Malgal, and the areas of Yemaek(예 맥:濊貊) inhabitants of Puyo(부여:夫餘) and Koguryo. Malgal is a people known as the descendants of Suksin before Chin(秦), Upnu during the period of Han(漢), and Mulgil(물길:勿吉) during the period of Later Wi (後魏). But various names were nothing but the ones whom Chinese used to the called people of the east-north differently at every times of the change of their dynasties. Briefly speaking, the names were not made by the people themselves, and the term Malgal was also not the execption. On the other hand, the term Malgal also appear in 『Samguk sagi』(삼국사 기:三國史記), going back even to the period of B.C. And the term was the name of dependant people who lived under the control of Koguryo near its frontiers.
Therefore the true meaning of Malgal should be found in such terms as Sokmal(속말:粟末), Packsan(백산:白山), or Heuksoo(흑수:黑水) which were added adjectively to Malgal. For example, it is true to say that Sokmal-Malgal are the inhabitants of the region of the Sungari River. Thus we may conclude that at least Packsan-Malgal and Sokmal-Malgal were surely the peoples ruled by Koguryo, and it is probable that other Malgals except Heuksoo-Malgal might have been so. They belonged racially to the ethnic group of Yemaek as Puyo and Koguryo did. And the relation between them and the royal family of Koguryo was formed not temporariness, but by the ethnic homogeneity which had lasted from the time immemorial. Then, we may conclude that contradictory theories regarding Tae Cho-yong as the special kind of Koguryo people and as the kind of Sokmal-Malgal can be compromised, and therefore he was a man 'from the region of Sungari River in Koguryo'.
What the history of parhae means to the Korean History is more clearly revealed by the fact that parhae, together with Silla, took a major role in the period of Southern and Northern countries. The history of Relationship between the two is divided into five stages. 1) the stage of foundation of parhae by Tae Cho-yong, with friendly relation between the two (698-713); 2) the stage of conflict between them from 713 to 785, due to the establishment and reinforcement of royal authority in parhae; 3) the stage of negotiation, under the circumstances of the decline of royal power in parhae and the struggle of Silla's nobility(785-818); 4) the stage of renewed conflict owing to the policy of territorial expansion by parhae and the close contact with T'ang by Silla(818-905); 5) the stage of negotiation in the course of expansion of Khitan, the fall of T'ang, the disintegration of Silla into the later Three Kingdoms, and the decline of parhae(906-926).
parhae's negotiation during the years of foundation was accomplished by the dispatch of ambassadors, and its purpose was prevent T'ang, their greatest enermy, from approaching Silla. This activity was successful in disturbing reemergence of relationship between Silla and T'ang when the Unified Silla awarded the title of Daeach'an(대아찬:大阿飡), the fifth office rank, their official post equivalent to five degree, to Tae Cho-yong, the founding King of parhae. And this means what Silla approved its foundation. By acting this way, they tried to build vertical relation with parhae as in terms of a moral obligation.
Their partership from the period of parhae's foundation began to get sour while the foundation of parhae was concretized. They took a worst turn under the circumstances that parhae carried out the recovery plan of old territory of Koguryo and improved the relation with T'ang. But Silla did not give up the policy toward the north. Their conflicts broke out at the time when Silla began to build castle in Kaeseong(개성: 開城), Hansanju (Gyonggido, Gwangju), and nothern border areas, respectively at the year of 713, 718, 721. On the other hand, the first dispatch of the ambassador to Japan had something to do with the accident of Heuksu-Malgal, but the important reason is parhae's policy to ckeck Silla. Therefore the accidents like Heuksu-Malgal and asylum of Tae Mun-ye's political exile into T'ang and later its attack at T'ang in 732, directly resulted from the conflict between them. And it is true that Silla proposed T'ang to attack parhae only by their own forces in response to the accident. And after that, the relation between parhae and Silla changed for the worse than that between parhae and T'ang. Moreover, it is affirmed that parhae was encouraged to invade Silla by Japan. Their intention was to divert the situation of internal politics, on the pretext of impoliteness shown to the Japanese ambassador by the royal family member of Silla and attempted to attack Silla by including parhae in the plan. Obviously, they tried to take adventage of the situation under the military confrontation between parhae and Silla.
The king of parhae's power began to be weakened by the building of strength by the noble, and continued to do so untill the time when moving the capital from Sangkyong-Yongcheobu(상경용천부:上京龍泉府) to Dongkyong-Yongwonbu(동경용원부: 東京龍原府) in 785. At this time they constricted a tie through negotiation for a short time with Silla which dispatched ambassadors twice. It was recorded in Samguk-sagi that Silla sent the ambassadors in 790, 6 years after the enthronement of King Wonsung(원성왕:元聖王), and in 812, 4 years after King Hondok(헌덕왕:憲 德王). But the intention of Silla to dispatch them to parhae was to turn the political contradictions, which two kings faced into the outside. They altogether were being met by the strong resistance by opposite factions and internationlly also could not have a good tie with T'ang because they enthroned by coup.
parhae and Silla returned to the state of conflict as soon as Tae In-su(대인수:大仁秀), the 10th king of parhae, ascended the throne in 818. At the background, Tae In-su was carrying a the name of Haedong songguk(해동성국:海東盛國), the policy of extension of territory, and Silla renewed a better relation with T'ang after T'ang's backuped Silla with a force 30,000 strong in the rebellion by Yi Sa-do(이사도:李師道) in 819, the 11th year of king Hondok's era, and was carring out the external policy in the direction of preparing the struggle against parhae. As a result, this relation of conflict affected positively upon the settlement of Silla's royal power, and king Hondok suppressed successfully the rebellion of Kim Heon-chang(김헌창:金憲昌). And externally Silla prepared for the struggle by force. It built the long defending line of 120 kilometers in the border regions in 826. Besides, the relation of dispute during this time was there in the diplomatic area between the two, and the competition between their students studying in T'ang. Two countries quarreled over the diplomatic rank in the court of T'ang. And they did in Binkongkwa(빈공과:賓貢科), the examination for foreigners, so consequently their relation turned into an irreparable state.
In the process of adherence of conflict between them, while Khitan was extending their power and T'ang was declining, Nambuk guk(Southern and Northern countries) began to change into the period of negotiation. The fact was discovered in the records that parhae, which was threaten by Khitan, requested assitance from Silla in 911 and kept the promise. In the second place, we can see the records that parhae had requested the help from Koryo of Later Three Kingdoms just before the fall, but under the conflicting state between parhae and Silla, the aggression of Khitan into parhae could not be blocked because Silla and Koryo rather helped Khitan in spite of the treaty with parhae because of the adherence of confrontation between the south and the north. Koryo was in need of Khitan because of the war with the Later Paekche. From that point, Koryo and Khitan had not showed any hostility each other until the fall of parhae. The relation of conflict between Koryo and Khitan, considered in the past, was corresponded with the fall of parhae in 926. For example, their relation of conflict, formed from the time when parhae's ethnic groups increasingly took refuge in Koryo, and the later Paekche and Khitan approached together, was translated into the relation between Koryo and Khitan in the early years of Koryo.
parhae and Silla could not overcome the conflict between them to the end. It resulted in the deepening of heterogeneity of their culture and intensified the conflict increasingly. The reasons why two countries had to face the limits in negotiation and could not overcome the conflict were as follows. Firstly, Silla's principal aim of negotiation with parhae was not real peace, but derived from and based upon the political interests of some specific faction. Secondly, parhae, always conscious of competition and struggle with Silla, chose for the occasions of negotiation with Silla, when not the years of stability but the years of emergency such as the foundation of the nation and the threat of the fall. Finally, the diplomatic relation between them was not independent one directed toward peace, but one directed toward a conflict which gave priority to the relation with T'ang and with Japan. However, in the process of its decline and fall, parhae asked for help, first of all, from Silla and the latter promised aids for parhae. Thereafter, the army for reconstruction of parhae asked Koryo for assistance, and then, after the movement of reconsruction failed and during the war between Koryo and Khitan, the leaders of the movement and their followers chose Koryo for their political refuge. Therefore parhae and Silla(later Koryo), despite of their long conflict and competition, seemed to have a sort of brethren feeling and communal conciousness each other, due to the homogeniety of blood. It would be in this respect that we can find what the history of parhae or the period of southern and northern country for Korean history in general means.