<P> After establishing the Han dynasty, Emperor Gaozu appointed princes and vassal kings to help him govern the Han Empire and gave each of them a piece of land . There were seven vassal kings who were not related to the imperial clan: Zang Tu, the King of Yan; Hán Xin, the King of Hán; Han Xin, the King of Chu; Peng Yue, the King of Liang; Ying Bu, the King of Huainan; Zhang Er, the King of Zhao; Wu Rui, the King of Changsha . However, later, the emperor became worried that the vassal kings might rebel against him because they after all had no blood relations with him . Han Xin and Peng Yue were (falsely) accused of treason, arrested and executed along with their families . Ying Bu and Zang Tu rebelled against him but were defeated and killed . Only Wu Rui and Zhang Er were left . </P> <P> The Xiongnu in the north had been a threat since the Qin dynasty . Qin Shi Huang had sent the general Meng Tian to oversee the defences on the Qin Empire's northern border and the construction of the Great Wall to repel the invaders . Meng Tian achieved success in deterring the Xiongnu from advancing beyond the border . However, after the Qin dynasty collapsed, the Xiongnu seized the opportunity to move south and raid the border again . In 201 BC, Hán Xin (King of Hán) defected to the Xiongnu leader, Modu . In the following year, Emperor Gaozu led an army to attack the Xiongnu but was besieged and trapped by the enemy at the Battle of Baideng . Acting on Chen Ping's advice, he bribed Modu's wife with gifts and got her to ask her husband to withdraw his forces . Modu did so . After returning to the capital, Emperor Gaozu initiated the policy of heqin, which involved sending noble ladies to marry the Xiongnu leaders and paying annual tribute to the Xiongnu in exchange for peace between the Han Empire and the Xiongnu . </P> <P> Emperor Gaozu was wounded by a stray arrow during the campaign against Ying Bu . He became seriously ill and remained in his inner chambers for a long period of time and ordered his guards to deny entry to everyone who tried to visit him . After several days, Fan Kuai barged into the chambers to see the emperor and the other subjects followed behind him . They saw Emperor Gaozu lying on his bed and attended to by a eunuch . Fan Kuai said, "How glorious it was when Your Majesty first led us to conquer the empire and how weary we are now . Your subjects are worried when they learn that Your Majesty is ill, but Your Majesty refuses to see us and prefers the company of a eunuch instead . Has Your Majesty forgotten the incident about Zhao Gao?" The emperor laughed and got out of bed to meet his subjects . </P> <P> Emperor Gaozu's health deteriorated later so Empress Lü Zhi hired a famous physician to heal him . When Emperor Gaozu enquired about his condition, the physician told him that his illness could be cured, but the emperor was displeased and he scolded the physician, "Isn't it Heaven's will that I managed to conquer this empire in simple clothing and with nothing but a sword? My life is determined by Heaven . It is useless even if Bian Que is here!" He refused to continue with the treatment and sent the physician away . Before his death, he said that Cao Shen could succeed Xiao He as the chancellor after Xiao died, and that Wang Ling could succeed Cao Shen . He also said that Wang Ling might be too young to perform his duties so Chen Ping could assist Wang, but Chen was also qualified to assume the responsibilities of a chancellor all by himself . He also named Zhou Bo as a possible candidate for the role of Grand Commandant . He died in Changle Palace (長樂 宮) on 1 June 195 BC and was succeeded by Liu Ying, who became historically known as Emperor Hui . </P>

Who became the first chinese ruler to claim the title of emperor