Early relations between Korea and Japan

Relations between Japan and Korea have always been complicated over the centuries, just as they are now but usually the emphasis has been on the modern period or medieval samurai period. This post is a chance to explore far earlier times between Japan and the Korean peninsula and how they would give and take with each other. Much of the info here I learned while reading a young-adult history manga featuring the famous character Ryō-san: 両さんの日本史大達人 (ryōsan no nihonshi daitatsujin, Ryo-san’s “Great People of Japanese History”).

It’s generally accepted history now that during the prehistoric Yayoi Period and Kofun Period contacts with the mainland increased. Evidence shows Northern Wei-Dynasty China had contacts and even exchanged gifts, but by the sixth century AD Japan’s Yamato kingdom was getting intricately involved in Korean politics in a bilateral way.

Korea at this time was divided into three major Kingdoms plus minor city-states to the far south. The big players were Goguryeo who ruled the northern half plus large areas of Manchuria, Baekje¹ who ruled the southwest around present-day Seoul and Silla who ruled the southeast. In Japanese these were called Koukuri (高句麗) for Goguryeo, Kudara (百済) for Baekje and Shiragi (新羅) for Silla. Meanwhile the city-states to the south were called Kaya (伽耶).

Japan’s relations with these three kingdoms often moved around. At times, they may pick temporary alliances with each other, then attack each other. But for various reasons, Japan’s Yamato kingdom developed closed ties to Baekje in particular. Indeed, Baekje is in great part responsible for the importation of Buddhism, Chinese characters and critical information about the mainland that formed crucial aspects of Japanese culture.

In Korea (?) at a place called kōtaiōhi (好太王碑), there is a stone stele recording a battle between the combined forces of Baekje and Japan’s Yamato kingdom against the Goguryeo and Silla. Later, in 663, Baekje faced invasion by Tang-Dynasty China and Silla, and Japan again came to its defense. The records show that Japan’s Yamato kingdom sent a fleet of ships to Baekje, but were crushed at the battle of Hakusonkō (白村江), and Japan withdrew. Ultimately, the kingdom of Silla won the conflict and unified the Korean territories, but the northern areas once ruled by Goguryeo persisted as the kingdom of Balhae that Sugaware no Michizane and the Heian Court maintained close relations with.

Meanwhile, after the crushing defeat and fall of Baekje, Japan feared invasion by Silla and China, and bolstered defenses in the island Kyushu, in the form of Mizuki (水城) Castle and Yamajiro (山城) Castle.

But relations with the Korean kingdoms then were not all related to warfare. For example, Prince Shotoku is said to have received his Buddhist education from bhikkhus (monks) from both Baekje and Silla. As stated earlier, relations with Korea allows Japan to get access to critical technology, information without the convoluted process of sending expeditions to China and paying tribute as a vassal state like many other Asian kingdoms did.

Also, the famous Soga Clan (蘇我) that dominated politics during the Asuka Period have ancestry that are said to be descended from Baekje and Goguryeo. Not surprisingly, the Soga Clan was an active supporter of Buddhist religion from the mainland while their enemies the more “native” Mononobe Clan supported the native Shinto religion instead, leading to conflicts and the eventual demise of the Mononobe. The Soga Clan’s victory under Soga no Umako (蘇我馬子) allowed him to appoint and assassinate Emperors at will, such as Emperor Sushun.

This post is a brief look at early relations between Korea and Japan. The relations were often bilateral, and complicated by the conflicts between the various kingdoms of Korea, as well as relations with China and its various dynasties. In addition to importing critical culture aspects from Korea, powerful clans in Japan at the time could claim descent from Korea, and in later years, Korea continued to provide a door to the mainland even when Japan had isolated itself from China.

¹ In Korean language, the “b” and “p” sound are almost the same, as are “r” and “l”. The letter is the same, but it’s pronounced slightly different depending on its position in a word, which leads to confusion when Romanizing Korean words. Is it a B or P? The point is, is that Baekje can be rendered as Paekche or other variations, and still be pronounced the same. Same is true with other Korean words, places, etc.