Yassa (alternatively: Yasa, Yasaq, Jazag, Zasag, , Ikh Zasag) was the oral law code of the Mongols declared in public in Bukhara by Genghis Khan de facto law of the Mongol Empire even though the "law" was kept secret and never made public. The Yassa seems to have its origin as wartime decrees, which were later codified and expanded to include cultural and lifestyle conventions. By keeping the Yassa secret, the decrees could be modified and used selectively. It is believed that the Yassa was supervised by Genghis Khan himself and his stepbrother Shikhikhutag, then the high judge (in ) of the Mongol Empire. Genghis Khan appointed his second son, Chagatai (later Chagatai Khan), to oversee the laws' execution. Overview The Yasa decrees were thought to be comprehensive and specific, but no Mongolian scroll or codex has been found. There are records of excerpts among many chronicles including Makrizi, Vartan, and ibn Batuta. Moreover, copies may have been discovered in Korea as well. The absence of any physical document is historically problematic. Historians are left with secondary sources, conjecture and speculation, which describe much of the content of the overview. Historical certainty about the Yassa is weak compared to the much older Code of Hammurabi (18th century BCE) or the Edicts of Ashoka, (3rd century BCE). The latter was carved for all to see on stone plinths, 12 to 15 m high, which were located throughout Ashoka's empire (now India, Nepal, Pakistan and Afghanistan). The Yassa, which is thought to be written in the Uighaur Mongolian script and written on scrolls, was preserved in secret archives and known only to and read only by the royal family. Beyond being a code of laws, the Yassa may have included philosophical, spiritual and mystical elements and so may have been thought of as a quasi-sacred or magic text. The exoteric aspect of Yasa outlined laws for various members of the Mongol community such as soldiers, officers and doctors. The Yassa aimed at three things: obedience to Genghis Khan, a binding together of the nomad clans and the merciless punishment of wrongdoing. It concerned itself with people, not property. Unless a man actually confessed, he was not judged guilty. The purpose of many decrees was probably to eliminate social and economic disputes among the Mongols and future allied peoples. Among the rules were no stealing of livestock from other people, the required sharing