Ashoka Rock Edict 1 (c. 257 BCE, already recorded as this entity's origin-start-year) shows royal commitment to vegetarianism and a ban on animal sacrifice in the Maurya Empire, but the sources consulted (the Buddhist vegetarianism and Buddhist cuisine Wikipedia articles, and the Emperor Wu of Liang Wikipedia article, checked for a later Chinese Buddhist monastic vegetarianism edict) describe the Theravada/Mahayana divergence on meat-eating as gradual, unfolding over centuries with no single codifying event or year named.
What would resolve this A dated primary or secondary source naming a specific edict, monastic code revision, or council ruling that formally codified Mahayana monastic vegetarianism, giving a defensible close to the origin period Ashoka's edict began.
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