The Yassa (also written Yassaq, Yasak, or Dasa) was the legal code promulgated by Genghis Khan at the kurultai of 1206 and supplemented by his successors. It was the legal foundation of the Mongol Empire and remained the basis of Mongol law for the next century and a half. The Yassa was not a comprehensive civil code in the modern sense; it was a tightly focused set of rules that regulated military service, hunting, hospitality, religious freedom, theft, adultery, and a list of capital crimes. Its central principle was that the security of the army and the unity of the people stood above the interests of any individual or family.
A critical caveat: the Yassa is one of the most cited and least well-preserved legal codes in the history of Eurasia. The original text was, by tradition, written down in a single copy that was kept at the imperial treasury, and that copy is now lost. What we know of the Yassa comes from the Secret History of the Mongols, the chronicles of Persian historians (Juvaini, Rashid al-Din), the testimony of European observers (John of Plano Carpini, William of Rubruck), and from later Russian and Chinese legal sources that purport to quote the Yassa. The result is a body of law that is consistently described across the sources but not always consistently quoted, and the modern academic consensus (de Rachewiltz, Ratchnevsky, Allsen) is that there is no single “original” Yassa in the way that there is an original Codex Justinianus. The Yassa is best understood as a living body of practice, supplemented by the Yarligh (imperial edict) of each khan, rather than as a single fixed text.
The Word “Yassa”
The word Yassa (modern Mongolian zasag, modern Turkish yasa) is a Turkic-Mongolian term meaning “law,” “ordinance,” or “commandment.” It is not, despite a popular claim sometimes made, the source of the English word yashmak (a veil); the English yashmak is a 19th-century borrowing from Turkish yaşmak, and the two are unrelated to yasa. The word is, however, the direct ancestor of the Russian yasak (yoke, tax, oath) and of the modern Mongolian zasag (law, regulation).
The Contents of the Yassa
The contents of the Yassa are known from the Secret History, from the Persian chronicles, and from the European observers of the 1240s and 1250s. The major provisions, in the order in which they are usually cited, are:
Military service
Every able-bodied male between the ages of about fifteen and seventy was required to serve in the army when called, on pain of death. The Yassa required every warrior to maintain a certain number of horses (the standard figure is three remounts per archer), a certain amount of equipment (a recurved bow, a quiver of arrows, a sword, a lasso, a felt tent), and a certain amount of provisions. The Yassa required every warrior to share his booty with his commander and with the khan, on pain of death, and it prohibited the looting of a battle before the official end of the engagement. The military provisions were the heart of the Yassa and the most strictly enforced.
Hunting
The Yassa established a strict code of hunting practices. There was a prohibition on hunting during certain seasons (the moult season, when the animals were shedding and the meat was poor), a prohibition on killing certain animals (the pregnant mare, the nursing doe), and a prohibition on the use of certain methods of hunting (the net, the snare, the noose). The Yassa also required the warriors to gather for the nerge, the great annual hunt, which was both a training exercise and a source of food for the army. The nerge was a circle, several days’ march across, in which the warriors drove the game into a tightening ring; it was the most realistic training the army got for actual battle, and it was the model for the later Mongol practice of battue-style campaigns.
Hospitality
The Yassa required every household to provide food and lodging to travellers on imperial business, and to any traveller who carried a paiza (imperial passport). It required every traveller to be received with hospitality by the householders, and it required the householders to report the presence of strangers to the local authorities. The provision is the ancestor of the yam postal system and of the obligatory hospitality that was a feature of steppe life well before the Yassa.
Religion
The Yassa established the principle of religious freedom, requiring the Mongols to tolerate all religions and to refrain from persecuting the followers of any faith. The Yassa also required the Mongols to pray in whatever tradition they chose, and it prohibited the Mongols from favouring one religion over another. The provision is well attested in Juvaini, in Carpini, and in the Secret History; it is the legal basis for the famous “religious tolerance” of the Mongol court. (The modern judgment — see Allsen 2001 — is that the Yassa’s religious freedom was pragmatic, not pluralist in the modern sense: the Mongols supported all organized religions because each was a useful channel of legitimacy, not because they had any philosophical commitment to pluralism.)
Theft, adultery, and capital crimes
The Yassa established a uniform system of punishments, with the death penalty for the most serious crimes (theft, adultery, the unauthorized sale of a female relative, the harbouring of a runaway slave, the false witness in a capital case) and corporal punishment or fines for lesser crimes. The death penalty for theft on the imperial road is the most-cited single provision of the Yassa; the Yassa also established the death penalty for finding a lost animal and not returning it, and for the urination in standing water (a steppe hygiene rule that was important when the same water was used by the herds).
Postal relay
The Yassa also established the yam — the postal relay system that would become one of the most important institutions of the Mongol Empire. The Yassa required every local authority to maintain a relay station, to provide fresh horses, and to feed the imperial messengers. The yam provisions were probably promulgated in the 1220s, after the conquest of northern China, where the Jin and the Song had maintained similar institutions.
The Enforcement of the Yassa
The Yassa was enforced with extraordinary severity. Carpini, who had seen criminal law in the Latin West, in the Rus’ principalities, and in the Mongol court, recorded that the Yassa’s enforcement was, by contemporary European standards, both exceptionally severe and exceptionally consistent. (Carpini’s specific examples — death for theft, death for adultery, death for finding a lost animal and not returning it — are widely quoted, and the standard modern judgment is that Carpini was probably correct about the existence of these provisions but may have overstated the consistency of their enforcement. The Jochid and Ilkhanid Yassa traditions do not always agree on which crimes carried the death penalty.)
The enforcement of the Yassa was carried out by a network of judges (jarghuchi) and administrators (bitigchi), who were appointed by the khan and who were responsible for the administration of justice in the territories of the empire. The judges were required to apply the Yassa uniformly, and they were required to report to the khan on the cases they had heard. The jarghuchi were Borjigin princes or close associates of the Borjigin; the bitigchi were drawn from the Uyghur, Chinese, and Persian scribal classes.
The Legacy of the Yassa
The Yassa was the legal foundation of the Mongol Empire and remained the basis of Mongol law for the next century and a half. The Yassa was translated into Chinese, Persian, Russian, and other languages, and many of its provisions survived in regional law long after the empire itself had disappeared. The most important of these provisions was the principle of religious freedom, which was eventually incorporated into the legal traditions of the successor states.
The Yassa was a major influence on the legal traditions of the successor states. The Yuan Dynasty in China adopted a modified version of the Yassa, which was applied to the Mongol and Turkic peoples of the empire alongside the Chinese legal code. The Ilkhanate in Persia adopted a modified version of the Yassa, which was applied alongside the sharia to the Muslim and non-Muslim populations. The Golden Horde applied a modified version of the Yassa to the Mongol ruling class and to the Turkic steppe population, while leaving the Russian principalities under their own customary law and the Russian Orthodox Church under its own canon law. The principle that the Yassa applied to the ruling class and a different law to the subject population is the real legal legacy of the Yassa; it is the model that the Russian Empire followed in the 16th and 17th centuries, and that the Qing Empire followed in the 17th and 18th centuries.
The Yassa is often claimed as a precursor of modern international law and modern human rights. The claim is overstated. The Yassa was a tribal legal code applied to a multi-ethnic imperial population, and its enforcement was, by modern standards, both arbitrary and severe. The provision of religious freedom is real and important, but it was a pragmatic religious freedom, not the pluralist religious freedom of the late-20th-century West. The honest modern judgment is that the Yassa was an important medieval legal code, that it was a major instrument of the Mongol conquests, and that its religious-freedom provision was a real innovation in the medieval world — but that it was not, in any direct sense, a precursor of modern human rights.
Sources
- Igor de Rachewiltz, ed. and trans., The Secret History of the Mongols (2 vols., Brill, 2004–2013), vol. 1 commentary.
- Paul Ratchnevsky, Genghis Khan: His Life and Legacy (Oxford: Blackwell, 1991), ch. 7.
- David Morgan, The Mongols (2nd ed., Oxford: Blackwell, 2007), ch. 2.
- Thomas T. Allsen, Commodity and Exchange in the Mongol Empire (Cambridge, 2001), introduction.
- John Man, Genghis Khan: Life, Death and Legacy (London, 2004), ch. 8.
- John Andrew Boyle, trans., The History of the World Conqueror by Juvaini (2 vols., Manchester, 1958), vol. 1.
- W. M. Thackston, trans., A Critical Edition of the Compendium of Chronicles by Rashid al-Din (Cambridge, MA, 1998–1999).
- Christopher Dawson, ed. and trans., The Mongol Mission: Narratives and Letters of the Franciscan Missionaries in Mongolia and China in the 13th and 14th Centuries (New York, 1955) — for Carpini and Rubruck.