西南夷列传 — Shiji

The chiefs of the southwestern barbarians numbered by the tens, with Yelang the greatest. West of them, the various Mimo clans also numbered by the tens, with Dian the greatest. North of Dian, the chiefs numbered by the tens, with Qiangdu the greatest. These peoples all wore their hair in topknots, cultivated fields, and lived in settled villages.

Beyond them to the west, from Tongshi eastward and north to Yeyu, were the Xi and Kunming peoples. They braided their hair and migrated with their livestock, having no fixed dwelling places and no chiefs of their own—their territory spanned several thousand li.

Northeast of the Xi region, the chiefs numbered by the tens, with Xi and Zongdu the greatest. Still further northeast, the chiefs numbered by the tens, with Wumang the greatest. Their customs varied between settled life and migration, and they dwelt west of Shu.

Northeast of Wumang, the chiefs numbered by the tens, with Baima the greatest. All of these were Di peoples. These were the various barbarians beyond the southwestern borders of Ba and Shu.

Zhang Qian therefore strongly urged that Daxia lay to the southwest of Han, admired Chinese civilization, but was distressed that the Xiongnu blocked the route. He argued that if a passage could truly be opened through Shu, the road to Shendu would be convenient and short, beneficial without any harm. Thereupon the Son of Heaven commanded Wang Ranyu, Bo Shichang, Lü Yueren, and others to go secretly out from the west of the Western Yi and make their way to seek the country of Shendu. When they arrived in Dian, the king of Dian, Chang Qiang, detained them and sought to open a route westward, sending out more than ten parties. After more than a year, all were blocked by the Kunming people, and none could get through to Shendu. The king of Dian said to the Han envoy, 'Which is greater, Han or I?'—and the Marquis of Yelang likewise asked the same.

When the Han dynasty rose, these states were all abandoned. The Han reopened the old Shu border passes. Men from Ba and Shu secretly ventured out as merchants, trading for Zong horses, Bo slaves, and mao cattle—transactions that brought great wealth to Ba and Shu.

In the sixth year of the Jianyuan era (135 BCE), the Grand Protector Wang Hui launched an attack against Eastern Yue. When Eastern Yue assassinated King Ying to appease the Han, Wang Hui used this military momentum to send the Panyang magistrate Tang Meng to secretly persuade Southern Yue. During a meal at the Southern Yue court, Meng was served Shu gouqiang sauce. When he asked where it came from, the reply was: "From the northwest, via the Zangke River. The river is several li wide and flows beneath the walls of Panyu."

Returning to Chang'an, Tang Meng inquired of Shu merchants. One told him: "Only Shu produces gouqiang sauce. Most of it is secretly sold in Yelang. Yelang lies on the Zangke River, which is over a hundred paces wide—wide enough for boats. Southern Yue uses wealth to subordinate Yelang, and its influence extends west to Tongshi, but even so, Yue cannot fully control or command these peoples."

The Emperor approved.

Tang Meng was appointed Vice Director of the Masters of Writing, leading a thousand soldiers and ten thousand transport personnel. They entered via the Zongguan pass of Ba and Shu and met the Yelang lord Duo Tong. Meng bestowed generous gifts upon him, explained Han's power and virtue, and proposed an agreement: he would establish official administration, and the lord's son would serve as magistrate.