Wiman Choson Rulers
Wiman was originally a refugee from the Chinese state of Yan. He succeeded in driving out King Jun of Go-Joseon and taking over the throne. He made the capital in Wanggeomseong (王險城), today's P'yŏngyang. Although cultually Sinicized, Wiman Joseon was not a colony of China.
Wiman Joseon expanded to control a vast territory and became strong economically by controlling trade between China's Han Dynasty and the outlying regions to the northeast. Feeling increasingly threatened by the growing Wiman Joseon, and fearing she would ally with the Xiongnu, Emperor Wu of Han China launched an attack on Wiman Joseon in 109 BC. After a year of battle, Wanggeomseong was captured and Wiman Joseon was destroyed. Han China established four commanderies in the captured areas, of which Lelang or Nangnang was the most important.
Rulers of Wiman Choson
初 王 (초왕)Wiman (Wiman)/卫满/衛滿 王 前 194- 전 147 ?
次 王 (차왕)전 147 ? - 서기전 128?
末 王 (말왕) 衛右渠 (위우거)Ugo (Youqu)/右渠王 서기전 128? - 108
Source :
http://en.wikipedia.org/wiki/Wei_Man
Gaozu's boyhood friend Lu Guan replaced Zang Tu as the King of Yen. During the winter of 196-195 BC, Lu Guan took up arms against the Han government in the Liaodong military district in eastern Yen. When Emperor Gaozu's armies crushed his rebellious warriors, Lu Guan moved his family and troops northward beyond the "Great Wall" to seek shelter among the Xiungnu. When Gaozu died in 195 BC, nine of his sons and relatives ruled kingdoms.
http://koreanhistoryproject.org/Ket/C01/E0111.htm
Lu Guan, the King of Yen, initiated a revolt in the Liaodong military district of eastern Yen during the winter of 196-195 BC. After Emperor Gaozu's armies suppressed the rebellion, Lu Guan moved his family and troops beyond the "Great Wall" to seek shelter among the northern Xiungnu. One of Lu Guan's lieutenants, Wiman, and about one thousand of his followers escaped through the stockade along the Liao River frontier dressed as local nomads. They crossed the Yalu River into northwestern Korea, where they surrendered to Ki Chun, the ruler of Old Choson. The ambitious Wiman asked if he and his followers could live among the Chinese refugees settled in western Old Choson and would Ki Chun entrust him with the defense of the kingdom's border with Yen. Wiman must have left quite an impression on Ki Chun, who not only granted his request, but appointed him lord over a thirty-mile stretch of the western frontier.
Wiman developed a strong power base over the years, garnering support from among the thousands of Chinese refugees still moving into Old Choson. At one point, Wiman sent an urgent message to Ki Chun alleging that he was being attacked on all sides. He requested permission to return to the capital at Wang'gom-song (near P'yong'yang) to guard the king. Following close on the heels of that message, Wiman marched a small army into the ancient capital, drove Ki Chun from the city, and proclaimed himself the new leader of Old Choson. Ki Chun and his retinue fled south down the peninsula where he established himself among the Mahan tribes and broke off all relations with his former kingdom.
Wiman soon created the kingdom of Choson, a new confederation that included many of the men from the Old Choson power structure and which bore all the hallmarks of the much stronger Han Chinese culture. With the Han Chinese preoccupied by internal politics and continuous threats from the Xiungnu, Wiman blocked any potential threat from China by reaching a defense agreement with the Chinese governor of Liaodong. No longer worried about attacks from the west, Wiman directed improvements to strengthen Choson's economy and military power. He used his newly developed strength to extend Choson's authority across the Korean peninsula. He pushed southward through the Chabiryong Pass to the Han River and subjugated the neighboring state of Chinbon. In the northeast, Wiman's forces conquered the Imdun tribes in the southern Hamgyong region. At its height, Wiman Choson controlled several hundred miles of territory across the waist of the Korean peninsula. With a new administrative structure in place and a reliance on the sophisticated knowledge of iron culture brought by migrant Chinese artisans, Wiman Choson began a period of rapid progress.
Ever mindful of the bloody price of conquest, China viewed any expansionist behavior of Choson with great alarm. Choson had become a refuge for hundreds of Chinese dissidents, particularly in the Liaodong River valley, and relations between the Changan court and King Ugo, Wiman's grandson, were not good. Elements within the Han court, worried that Choson would side with China's enemies at any moment, exerted ever-increasing pressure on Wu Di to remove the danger to the Liaodong region by asserting positive Chinese control over the Korean peninsula. The Han Emperor, troubled by a court in decline for some time, gradually came to fear the possibility of an alliance between Choson and the Xiungnu in the north.
The strained relationship between China and Choson eventually ruptured; not because of a military alliance with the Xiungnu, but because of a trade dispute. The State of Chin, isolated on the southern end of the Korean peninsula, had a strong desire to enjoy the benefits of Han China's new metal technologies. King Ugo regarded the southern peninsula as part of his domain and barred any direct contact between China and the smaller peninsula states. Since Choson straddled the only land connection with China, Choson effectively became the economic middleman on the Korean peninsula. King Ugo jealously guarded his trade connections with the Han Chinese and moved to increase the profitability of those connections and strengthen Choson in the process. Since Ki Chun had earlier cut off relations between the State of Chin and Choson, he decided to bypass Choson altogether and attempted to establish direct contact with the Han court in Changan. Choson frustrated any hope for direct trade by forcibly preventing the his envoys from ever reaching China.
Choson's interference with Chin's attempt to seek recognition from Changan became a source of real friction between Choson and Han China. Despite Emperor Wu's repeated attempts to negotiate a settlement with King Ugo, his personal envoys to Wang'gom-song had little impact on their strained relations. The Emperor even went so far as to attempt to divide the peninsula by exploiting cultural differences between the ruling aristocracy and the people in Choson and the provinces of the southern peninsula. In the spring of 109 BC, the Han court sent an envoy named She He to inform King Ugo of China's displeasure. During She He's return trip to China, he murdered his military escort and later boasted he had killed a Choson army general. The Han court rewarded She He for his action by appointing him commander of the eastern sector of Liaodong. The implication of that appointment did not go unnoticed in Wang'gom-song. Later that summer, a group of warriors dispatched from King Ugo's court exacted a measure of revenge by catching up with She He and brutally murdering him.
Border clashes between Choson and Han China escalated throughout the year. Using She He's death as a pretext for action, Emperor Wu dispatched two large armies against King Ugo's kingdom in the autumn of 109 BC. The first expedition, led by Yang Pu, crossed the Gulf of Bo Hai and landed on Korea's west coast. General Xun Zhi marched a second army into Korea from the Liaodong region. Choson's skill in metal culture was every bit as good as China's at the time and King Ugo commanded well-equipped armies. Choson troops engaged and soundly defeated Xun Zhi's army in Korea's northern mountain passes and routed Yang Pu's bogged down assault against Wang'gom-song in the south.
The Choson army's stiff resistance and the inability of generals Hsün and Yang to cooperate with each other prolonged open hostilities between Han China and Choson throughout the year. While the two Chinese armies pulled back to regroup and lick their wounds, Emperor Wu sent yet another envoy to Wang'gom-song in an attempt to overawe King Ugo. This time it appeared that a settlement would be reached. King Ugo agreed to send his own son to the Han court to affect an agreement. Trouble developed on the banks of the Yalu River however, when the young Choson Crown Prince refused to dismiss his armed guard before crossing into Chinese territory. Angered by the refusal, Chinese envoy Wei Shan refused him permission to proceed. When word of this ill-advised behavior reached China, Emperor Wu ordered Wei Shan's execution.
While Choson warriors successfully managed to hold off the Chinese in the north, internal dissension and chaos intensified among Choson's ruling class and the court at Wang'gom-song. During this troubled period a new flood of refugees left Choson. Some fled because they no longer accepted northern rule, while others departed for purely political reasons. Yok-kye, one of King Ugo's high ministers, could not persuade the king to drop the policies that eventually led to the break with China. When it became clear King Ugo would not change his position, Yok-kye reportedly fled south to the State of Chin with over two thousand households. Among the many refugees were skilled metallurgists, competent rice farmers and people experienced in the new Chinese arts of governing. Not only were they eagerly welcomed, but their new knowledge and skills played an important role in the future development of southern Korea.
Communities in southern Korea coalesced around new power centers, creating three new peninsula kingdoms known collectively as the Samhan States. 
In the T'ung-chia and Yalu River basin region, the Yemaek people consolidated their strength under the leadership of Lord Namnyo, who reportedly ruled a population of some 280,000 people.
Frustrated by the inability of his army to conquer Choson, Emperor Wu ordered an investigation of the military situation on the peninsula. The inquiry led to the arrest and decapitation of General Yang Pu and the transfer of his entire command to General Xun Zhi. General Xun received new orders for an all-out assault against Choson. In the summer of 108 BC, General Xun Zhi's army overran Choson. The increased fighting around Wang'gom-song triggered open dissension within the ruling class and intensified the activities of a peace faction within Choson's royal court. Once the court sensed that all was lost, Choson no longer had the heart to continue. The Choson army held off the Chinese for a time, but increasing defections gradually weakened their ranks and General Xun captured Wang'gom-song in a matter of days.
Han Chinese soldiers conquered adjacent lands in southern Korea and southern Manchuria, meeting only token resistance. In a desperate move to end the bloodshed, a secretive group of Choson court ministers, some of whom were Chinese, brutally assassinated King Ugo and formally surrendered the kingdom to China. The Chinese handsomely rewarded collaborators in Ugo's court who switched sides at the last moment, ensuring their families would continue to enjoy high social status. Others were not so fortunate. Many fled the country. Some even sailed south to Japan. The once ambitious Korean kingdom did to itself what Emperor Wu's armies could not. Wiman Choson perished.