(1) Societies and Economies of the Three Kingdoms

In the Three Kingdoms, class distinctions between the aristocracy, commoners and menials were very rigid. The central aristocrats and royal families were in charge of the government, economy, and culture, and exercised many privileges. The commoners were mostly self-sustaining farmers who cultivated their own lands and paid taxes to the government. The menials were slaves and villagers in Pugok who composed the lowest stratum in society.
The ruling classes were the families of the kings and queens. In Koguryo the Ko clan of Kyerubu became the royal family, and in Paekche the Puyo clan was the royal family. In early Shilla the three clans of Pak, Sok and Kim alternated in succeeding the throne, but after King Naemul, the Kims inherited the throne. In Shilla there was a strict system of personal status called Kolp'um which was distinguished into Songgol, Chin'gol (royal family) and 6,5,4,-tup'ums (classes of aristocrats). Among them many aristocrats of the 6-tup'um chiefly engaged in scholarly pursuits and religion.
In Shilla, there was the Hwabaek system in which representative aristocrats gathered to determine important affairs of the state unanimously. There was also a youth organization called Hwarang-do (Flower Youths) which trained many capable men who, following the five secular commandments of Won'gwang, received mental and physical training and had loyalty to the state inculcated in them. The Three Kingdoms developed as ancient kingdoms readjusting their political organizations. In Koguryo, there were 12 classes of bureaucrats below Taedaero and in Paekche there were 16 classes below Chwap'yong.
In Shilla, there were 17 classes of bureaucrats below Ibolch'an. Advancement to officialdom was strictly restricted to those of Kolp'um status, and the political activities of the Three Kingdoms were carried out through the unified efforts of the aristocrats. Taedaero in Koguryo and Sangdaedung in Shilla (equivalent to premier) were chosen at meetings of aristocrats.
In the Three Kingdoms, agriculture developed as the most important industry. In Paekche and Shilla, irrigation facilities expanded with rice farming. In Koguryo, millet, soybeans and other dry farm crops were the chief crops. In addition, handicrafts were also developed. In the Three Kingdoms, the practice of usury boomed, and many commoners were driven to become slaves as a result of heavy debt. In Koguryo, the government practiced Chindae-pop, a law of loaning grain in the spring and being repaid in the autumn, to prevent impoverished peasants from turning into the slaves of aristocrats.

(2) Transmission and Development of Buddhism

While the Three Kingdoms developed as ancient kingdoms, they required a new religion for spiritual unity of their people. Just at this period, Buddhism, which began in India, was introduced into the Three Kingdoms through China. In Koguryo, during the reign of King Sosurim, Shundao from Former Qin in northern China introduced Buddhism in 372. In the kingdom of Paekche, an Indian monk named Marananta arrived by sea through Dong-Jin China to introduce Buddhism in 384. Buddhism was first introduced to Shilla in 384 by Mukhoja, a priest from Koguryo, but it was subjected to oppression. After a hundred years, following the martydom of a famous monk named Yi Ch'a-don, King Pophung officially recognized Buddhism in 527.
Buddhism in the Three Kingdoms flourished with the support of the royal family and the aristocrats. In this way, Buddhism became the state religion, which contributed to the national defense. This was especially true in Shilla where Buddhism was combined with the development of the royal family to play a leading role as the national ideology. Taoism was also introduced to the Three Kingdoms. In the Sasindo drawn on the old tomb of Koguryo and in the Sangyong Munjon of Paekche, traces of Taoism can be found.

(3) Popularization of Confucianism and the Compilation of History

Upon entering the period of the Three Kingdoms, Chinese characters began to be widely used, and Confucianism and Chinese literature began to rise in popularity. In addition, the writing system of Idu was used in which Korean words were recorded by selecting the corresponding meaning and sounds in Chinese characters. Shilla's Sol Ch'ong designed this system Idu.
In Koguryo, a school called T'aehak was established in P'yong'yang to teach Confucianism, and schools called Kyongdang were set up in many districts to teach Chinese characters and military arts to the youth. In Paekche, the Ogyong scholars taught the Confucian classics to students.
All three kingdoms tried to compile their own histories. In Koguryo, 100 volumes of Yugi were compiled and under the reign of King Yongyang, Yi Mun-jin compiled them into five concise volumes. Ko Hung of Paekche compiled Sogi during the reign of Kunch'ogo, and Koch'ilbu of Shilla compiled Kuksa, a record of the national history under the reign of King Chinhung. But the history books compiled during the Three Kingdoms period have not survived to today.

(4) Art Activities of the Three Kingdoms

With an aristocrat-centered culture rising, refined and colorful aristocratic art developed, and simple traditional artwork remained among the people.
The arts of the Three Kingdoms developed in two fields-old tomb art and Buddhist art. Physical strength and passion overflowed in the Koguryo art work while elegant and refined beauty was characteristic of Paekche art objects, and Shilla art objects gradually displayed a beauty of harmony.
The famous old tombs of Koguryo are Changgun-ch'ong (Tomb of the Generals), Muyong-ch'ong (Tomb of the Dancers and Hunters), Ssangyong-ch'ong (The Double Pillar Tombs) and the Kangso-daemyo (The Great Tombs).
Among them, the Changgun-ch'ong is believed to be the tomb of King Kwanggaet'o. It is a big stone tomb with steps of seven-stories. The hunters and dancers drawn in the Muyong-ch'ong, pictures of warriors and their genre painted in the Ssangyong-ch'ong, and the pictures of 4 guardian spirits as embodied by different animals in the Kangso Big Tombs are all brilliant frescos which represent the ambitious spirit and customs of the Koguryo people at that time. Paekche's old tombs possess a powerful beauty in their architecture and frescos. The tomb of King Munyong is famous for the many burial accessories and the slate inscribed with the record of the deceased. Gold crowns and beautiful art works have been excavated from the old tombs of Shilla and the picture of a heavenly horse which represents Shilla's emblem has been found in the Ch'onmach'ong.
Among the stone pagodas of Paekche, the pagoda located on the site of Maitreya Temple in Iksan and the five-story stone pagoda on the site of Chongnimsa Temple in Puyo are the most renowned. In particular, the five-story pagoda on the site of Chongnimsa Temple, which is representative of Paekche art, is well balanced and is a beautifully executed masterpiece. The most distinct stone constructions of Shilla are the pagodas in Punhwangsa Temple and the Ch'omsongdae observatory.
Remarkable Buddha figures include the gold-plated figure of Buddha sitting with his legs half-crossed and Sosan's Three Buddhas of Ma'e. The former expressed elegance (frequently produced in each of the Three Kingdoms), and the latter represents the typical features of Buddhist images present in Paekche. It shows a thin mild smile on its face called "Paekche's smile."
From ancient times the Korean people have loved songs and dances. Among the songs of the Three Kingdoms, Hyesongga, a Hyangga (folk song) of Shilla, remains. Wang San-ak of Koguryo improved the seven-string instrument of China, Ch'ilhyongum, into Komungo and U Ruk of Kaya introduced the Kayagum to Shilla. Paekche music was introduced to Japan and influenced the development of Japanese music.