I think many civilizations independently invented it. The innovation that law is written down by lawmakers is not that hard to duplicate. If anything, the oppo

I think many civilizations independently invented it. The innovation that law is written down by lawmakers is not that hard to duplicate. If anything, the opposite happened and high frequency of common law in the world is purely because the British Empire was the largest empire to have ever existed and all states that utilize common law descend from the British Empire. Until the British Empire, common law existed only on the British Isles and the rest of the world had civil law.