III. UNIFIED SHILLA AND PARHAE
1. Development and Decline of Unified Shilla

(1) Adjustment of the Political System

Shilla, which unified the Three Kingdoms. readjusted its political and other ruling institutions, thus stablizing both government and society.
After unification, the royal powers of the King were strengthened as a result of the unbroken lineage from King Muyol, and the power of aristocrats was weakened. From then on, the powers of the Sijung, who served as executives and who promulgated the King's orders and enforced laws, were greater than the Sangdaedung, who represented the aristocracy. Marching abreast with many social developments, many offices were established, and schools known as Kukhak were set up to teach Confucianism.
Local administrative systems were also reorganized. During the reign of King Sinmun, the country was divided into nine provinces, and under each province, counties (Kun and Hyon) were organized. Five cities were stationed as the heads of these localities to make them the hearts of local government and culture.
Shilla reorganized and strengthened the military. In the central headquarters, nine Sodangs (king's guards) were stationed, and in the local areas, 10 Chongs were stationed in important locations of the nine provinces.
 
(2) Aristocrat-centered Economic Life
The economic life of unified Shilla prospered with the aristocrats at its center. The aristocrats received and owned large acreages of land, and also possessed wide meadows in the mountain valleys and islands. They also possessed many slaves and amassed huge wealth through the practice of usury.
The wealthy aristocrats who lived in luxurious houses fell into a life of extravagance and pleasure. In this way, the traditionally strong-spirited Shilla people began to decay spiritually.
 


Thin-ringed gold earings,
5th or 6th century.

 
On the other hand, farmers in the villages and menials, who lived in the special administration districts, Hyang, So, and Pugok, had to led difficult lives because of their heavy indebtedness to either the state or aristocrats. The government investigated the local lands, population, livestock and even the number of standing trees once every three years in order to administer the labor force and production resources.
 
(3) Social Changes During the Last Stage of Shilla
Shilla, which enjoyed prosperity for about 100 years after the unification, fell into hardship beginning with the latter half of the 8th century. The continuous royal line of King Muyol was broken with King Hyegong as the last of that lineage, and there was a scramble for the crown among the Chin'gol aristocrats.
As a result, in the later Shilla years, confusion was prevalent as 20 kings reigned during a 150-year period. In the countryside, Rebellions headed by Kim Hon-ch'ang sprung up to weaken the power of the central government.
When the government and society was in a state of confusion as a result of the scramble for the crown among the Chin'gol aristocrats, the local powers of the chieftains and sea captains gathered strength. As a good example, Chang Po-go maintained power over sea trade in the South and Yellow Seas and monopolized trade with both Tang and Japan to became the master of the sea for a time.
The local powers indigenous to their area had their independent ambitions, calling themselves city masters or generals. They were the chieftains who played important roles in weakening the royal structure of the Chin'gol government of Shilla.
On the other hand, impoverished peasants became either slaves or thieves. During the reign of Queen Chinsong, peasants rose up in rebellion everywhere, and Shilla fell into a swirl of civil wars.