1. Introduction

Western Han dynasty inherited from the Qin dynasty as an empire, and also its problems of recession and biggest enemy in the Northern frontier, the Xiongnu confederacy. Due to the inferior military power of the Xiongnu, the Han dynasty was forced to accept heqin peace treaties with unfavorable and, in many historians’ perspectives, humiliating terms. Until Emperor Wu (武帝) instigated the largest-scale territorial expansion, the heqin system reversed to a tributary system that governed the future Chinese-Barbarian relations.

Most scholars would agree that the heqin policy temporarily exchanged time for the Han court to preserve strength and build up national power. However, it came to an end due to constant breaches of the treaties by both the Xiongnu and Han sides, the failure to educate the Xiongnu about the Kinship ritual, and the expensive annual payments, as was thoroughly discussed in Discourses on Salt and Iron (yantielun鹽鐵論) to record a political meeting held in 81 B.C.

What is rarely mentioned is the symbolic and ritual propriety (liyi 禮儀) value of heqin to the Han court in strengthening the imperial order based on Confucian principles, which maintained political stability.

After looking into more evidence of Silk Road evolvement during the Han dynasty, impactful connections with the heqin policy were identified, which has not been specifically discussed in other research yet. This work will elaborate on the contributions heqin policy had on Silk Road trade development by answering the key questions of why the trade existed based on policy, when and how silk became the most popular goods, where the goods were traded and who were the key drivers and how stable Silk Road routes were built up. This work will also illustrate possible reasons why the large-scale Silk trade did not happen before heqin period.

Due to the limitation of evidence, this work will not intend to do quantitative analysis but more to show correlations.

2. Overview of Background for Heqin Policy

The Han dynasty was founded in 202 B.C., after the defeat of the first unified empire of the Qin dynasty. Different from Qin’s full adoption of Legalism (法家), the Han practiced a combination of Confucianism (儒家) and Legalism in theory to deal with their complex situation [1]. The Han court both struggled to recover from the recession left by Qin and faced strong confrontation from the Xiongnu confederacy to the north, the biggest enemy since Qin. After Xiongnu surrounded and forced founding Emperor Gaozu to surrender in 200 B.C., his minister Liu Jing (劉敬) proposed heqin policy. It created a new non-tributary relations format with foreign peoples that later dynasties continued to adopt when applicable. Later, Emperor Wu (武帝), with ambitions to conquer the Xiongnu, changed the strategy to launch wars. After a series of victories with the Xiongnu, the foreign policy of the Han transitioned from the heqin system to a Tributary system with foreign peoples.

3. Heqin Policy and Its Objectives

Prior to Shiji, the term heqin referred to the achievement of harmonious relations and on rare occasions it was used to describe peace agreements between clans and among states [2]. The actual term heqin to describe peace agreements with ritual or contractual elements first appeared with the Han-Xiongnu treaty signed in 198 B.C. after Liu Jing’s proposal, including the following items:

Marrying a Chinese princess to the chieftain (Shan Yu 單于)

The Han court agreed to send Xiongnu fixed annual payments for silk, wine, and grains.

The Han and Xiongnu to be equal (“brotherly”) states.

Set the Great Wall as the border between the Han and Xiongnu, “those who draw bows” to its north, and those who wear “caps and sashes” to the south.

This set the “old treaty” terms the later heqin during the Han dynasty would or tried to refer to. During Emperor Jing (景帝), opening up the border market was added to the heqin treaty.

Xiongnu and other barbarians were often described as greedy (tan 貪) for Chinese goods, like Liu Jing and Zhang Qian (張騫). As Nicola Di Cosmo described heqin policy is usually regarded a means of buy peace in exchange for goods [3]. The heqin treaty fulfilled Xiongnu’s main objectives for Chinese goods, setting up frontier and opening markets. Due to their superior military power, this sounded like one-way traffic to the Xiongnu. However, there was an important symbolic and ritual value of heqin to the Han court that is often underestimated. Under the heqin term, the annual payments made by the Han court were not considered as a tribute to the victor but as a ritual dowry to an equal. In Liu Jing’s proposal, the heqin policy will reverse Han- Xiongnu power relations after the Han princess gives birth to the next Xiongnu leader, who will not defy the Han emperor under the father-son (and grandfather-grandson) Confucian ritual propriety principles. Although Liu Jing’s heqin design failed to educate the Xiongnu with ritual principles and to govern the future Han-Xiongnu relations, its symbolic and ritual values played an important role in maintaining the Han court’s imperial image and as a Confucian society, which strengthened the political stability. This pattern has a long-lasting impact on the later dynasties.

There were 22 heqin records between Han and Barbarian states throughout the Han dynasty, mainly from Shiji, Hanshu, and Houhanshu [4]. Most of the heqin were with Xiongnu at the beginning of the Han dynasty. By Emperor Wu, he built an alliance with Wusun in Western Regions through two heqin marriages to “cut Xiongnu’s right arm”. By the time of heqin of Wang zhaojun (王昭君) with Xiongnu Shanyu Huhanye (呼韓邪單于) in 33 B.C. after he paid homage to the Han court and requested for heqin, the power relation was reversed back from heqin relations to the tributary system. Such foreign relations patterns governed the future Chinese-Barbarian relations during the Han dynasty, even if some later cases were under the name of heqin.

In general, the Han court’s objectives for the heqin were peaceful relations with the barbarians and the possibility of Sinicize them with the Confucian ritual principles. The barbarians were looking for Chinese goods, setting up frontier borders, and opening up border markets, which were fulfilled under the heqin framework in most cases.

Even though heqin bought time for the Han court to develop national power and strengthen political stability, the negative impact was constantly debated among scholars and ended the heqin policy during Emperor Wu. This work, however, identified heqin policy’s contributions to trade between Han and foreign countries, the later Silk Road trade, which will be elaborated further in the following section.

4. Heqin Policy’s Contribution to Silk Road Trade Development

To study heqin policy’s connection with the Silk Road trade, this paper will look into why the trade existed based on policy, who were the key drivers, what products were traded and when, where they were traded and how they were transported.

4.1. Policy

Han dynasty’s foreign policy was entirely linked with Xiongnu. Through the heqin policy, the Han and Xiongnu reached temporary peace to allow the Han’s military and economic growth. After Emperor Wu’s military success with the Xiongnu, Han’s foreign policy gradually transferred from heqin to “using barbarians to check or attack barbarians” (yi yi zhi yi以夷制夷) and included Xiongnu and Western regions under their tributary system. In return, the Han court provided them with many imperial gifts.

Regarding economic policy, Western Han’s primary focus was on agriculture, with commercial and industrial as secondary importance. Policy changes during Later Han included more favorable policies for trade development. Evidence tends to show that trade never ceased to grow and became a major revenue source for the Han dynasty [1].

For the Xiongnu, an important part of their economy was gifts and tributes and trade with foreign countries [1]. Heqin policy provided Xiongnu with large annual payments or gifts, which was consistent in the later tributary system with Western regions. Opening up border markets in the Heqin treaty reinforced barbarians' role as intermediaries in the foreign trade of Han China.

4.2. Products Traded and Timeline

According to a comprehensive study by Yu Ying-shih in his book Trade and Expansion in Han China, there were 5 main agricultural and industrial resources during the Han period: crops, lacquerwork, iron, copper, and silk. Silk, by far, was the most famous among all export goods, both in government and private business [1].

Silk production in China can be traced back to more than 6,000 years ago. It was considered a high-value gift with ritual meaning and had already been used since the Warring States period as an imperial gift and subsidy. Records show that during the Han dynasty, silk was also used as currency by envoys and merchants to pay their travel expenses and as payments to soldiers. This was consistent with the change of the medium of exchange from gold or copper coins in Western Han to silk in Later Han.

Large amounts of silk floss and fabrics were used as annual payments to the Xiongnu, with a traceable record of an increase of such annual payments mainly in silk of various kinds. The same trend was found for imperial gifts to Western regions after the Han court’s expansion. For example, towards the end of Emperor Wu’s reign, the Shanyu requested to resume heqin relations and asked for an increased annual payment of 10,000 pi of silk together with wine and grain. Table 1 shows the significant increase of silk in Han gifts to Xiongnu [1].

Table 1: The amount of silk in Han gifts to Xiongnu

As per excavation and record, silk was first available in Greece around 5^th century B.C. at very small sale. Chinese silk fabrics were known in Egypt around the 1st century B.C., and silk reached the Roman market estimated during Augustus’s reign (27 B.C.-A.D.14). This timeline could connect the supply of the large amount of silk as annual payments (since 198 B.C.) with when silk trade gradually flourished in foreign countries. As Owen Lattimore concluded, the primary export of silk may arise from gifts and subsidies acquired in surplus to dispose of in more distant markets [1]. It took a reasonable time to stabilize trade routes to Western countries after peace was achieved through heqin policy, then followed by Han’s expansion to Western regions. Later evidence that Chinese silk became an important raw material for the weaving industry in the Roman Orient is consistent with the records that it was mainly Silk floss and Silk fabrics in Han’s annual payments and imperial gifts, and the significant increase in amount. Chinese silk was the most cherished by foreign peoples among all the goods due to its great value, small bulk, and lightweight.

4.3. Merchants and Markets

For the foreign trade in Han China, there were mainly below types of markets with records:

Camp markets: for the stationed military forces to trade among soldiers, with commoners, and with barbarians.

Border markets: These are normally at a critical spot for defense. Xiongnu specifically requested in heqin treaty that the border market be opened up for the exchange of commodities, as well as fine Chinese food and wine.

Ordinary markets in frontier cities: wealth of these cities was often derived from international trade with barbarians. For example, Guzang (姑臧), the capital city of Wuwei province, was the wealthiest city in the area from trade with different barbarians.

Considering access to a large amount of silk from annual payments or imperial gifts to Xiongnu and Western regions, it is reasonable to estimate that the foreign silk trade was primarily linked with border markets and markets in frontier cities.

During the Han period, merchants were active, especially along the frontier areas. There were different types of merchants in the broader definition that involved foreign trade: the Han merchants, the barbarian merchants, the stationed military forces on the frontier, the envoys, and, of course, the foreign merchants mainly from Parthia, India, and Rome. The envoys played an important dual role as envoys and merchants; for example, it was a common practice to appoint merchants as envoys or tribute-bearers. The complex travel document requirements made it easier for envoys to travel around and look for profitable trade opportunities. There is no evidence showing the size of the heqin envoy group, but it should not be a small number as an imperial activity. Heqin policy can also increase the frequency of sending envoys compared with if at confrontation status, as was described by both Shiji and Hanshu that “envoys see each other alongside the highway.”

Through heqin policy, opening up boarder markets and increase of envoy merchants acted as important drivers for silk road trade development.

4.4. Transportation

Trade highly depends on transportation. Large-scale road and water construction in the Qin and Han dynasties was motivated by political and military considerations. Han China provided travelers with housing accommodations and horse stations. The merchants also used such transportation systems and accommodations for their trade activities. Heqin trip was a long journey from Chang’an to Xiongnu court or to Western regions, and it would accelerate the development of transportation and accommodation facilities.

Han China’s direct connection with Western regions was officially built up after heqin with Shanyu Huhanye in 33 B.C. As indicated in Hanshu, “by the time when Shanyu Huhanye paid homage at the Han court, (those peoples) all turned their respect to China.” The overland transportation routes between Han China with Western regions were thus stabilized after Zhang Qian’s first two explorations and then the peaceful and direct relations facilitated by heqin. Chinese goods, especially silk, can go from China's interior states to Western Regions as more stable routes, from which to Western countries and later named Silk Road. The main line may be briefly described as indicated in Trade and Expansion in Han China: “it began at Chang’an, went westward along the Gansu Corridor, crossed the Tarim Basin and Pamirs, then passed through what is now Turkestan (especially Samarkand) Iran, Iraq, and Syria, and eventually reached the Mediterranean.” [1].

There was scattered evidence from excavations and literature to show a high possibility of the existence of trade routes at the beginning of the Han period for Chinese goods to Western countries from Sichuan (四川) via Yunnan(雲南) to Burma to India and during later Han via Bactria to India to Western countries or via Parthia to further west. Both overland and overseas transportation were involved at different sections of the routes [5]. With the much higher risk involved in transportation by sea [1], it is normal that during the Han period, overland transportation for high-value goods like silk was considered a primary route, as an actual Silk “Road”.

5. Conclusion

To conclude, the heqin policy was a forced adoption by Han China due to the inferior military power of the Xiongnu. It exchanged time for the Han court to gain more national power and won later in wars with the Xiongnu during Emperor Wu’s reign. Typical heqin policy came to an end due to the failure to achieve the intended objectives from Han’s perspective for peaceful relations, Sinicize Xiongnu with Confucian principles, and the burden of expensive annual payments.

In other words, although not directly researched, this paper can still identify the heqin policy’s accidental contributions to Silk Road Trade development by connecting various pieces of evidence together, even if not as the originally designed objectives.

Heqin policy strengthened the political stability of the early Han period by its symbolic and ritual value as a Confucian society and exchanged time for the Han court to grow national power.

Heqin provided Xiongnu and other Western regions with large amounts of silk as annual payments or imperial gifts, which was a high-demand product in Western countries.

Opening up border markets, as what Xiongnu always requested in the Heqin treaty, together with different merchant groups, boosted foreign trade activities. Heqin process could increase the number of envoy-merchants.

Heqin facilitated peaceful relations and direct connections of Han China with Western regions. Stable trade routes linking interior China to Western regions to Western countries were built up that impacted the future Chinese foreign trade, known as Silk Road.

It is also understandable that large-scale silk trade evidence between China and Western countries was not found before heqin time due to a lack of policy support from the Han court, sufficient supply of goods - silk, markets, and transportation infrastructure boosted by heqin policy.

There is not enough evidence to do a quantitative analysis of how important the Silk Road trade is to Han China to get a better idea of its importance. For example, there is not enough evidence to calculate the contribution of foreign trade to the total revenue of Han institutions and the percentage of the total Chinese silk production that is for foreign trade or gifting. However, the linkage of different attributes at the same time can inspire new and possibly neglected perspectives.