Golden Law.
This is one of the two foundational artifacts of the Golden Races, consisting of nine components in total. Of these, only four are known to mankind by name: the Oathbook, the Chapter of the Golden Dragon, the Titan's Promise, and the Blood of the Multitude.
The effects of the Titan's Promise and the Blood of the Multitude remain unknown, but the Oathbook and the Chapter of the Golden Dragon are absolutely powerful tools for unifying civilizations.
The Oathbook can eliminate the chains of suspicion among all races and civilizations, preventing them from immediately engaging in life-or-death struggles or distrusting each other upon meeting, which would ultimately only be resolved by the death of one party.
This is almost like a miracle!