User blog comment:Kaido King of the Beasts/Baseless Predictions/@comment-12333373-20140521103506

The ancient kingdom (in the void century) discovered and named the 9 ways of haki.

The kingdom was ruled by an empress and was populated both by men and females. Sometime during the war, the empress/country was betrayed by a man which caused the enemy (the 20 kings) to prevail. Discreetly the empress and some of her subordinates fled the country and settled on a distant island today known as Amason Lily. The 9 ways of haki was each repressented as a snake on their flag. Unfortunately most of the rare haki techniques has been forgotten.

Since many people (from the ancient kingdom) where captured, including people who could use haki, the most common haki techniques spread trough the world. But since they where difficult to learn, only some managed to use it and teach others.