User blog comment:The ASL Pirates/Haoshoku Haki Theory/@comment-10543621-20150217070723

Well, it's called conqurer's haki, As the name suggests, people who have the heart of a conqurer would probably have it, Ya know like leadership qualities and extremely strong will and stuff. So far, all users were commanders who are able to inspire many others. Many have 'royalty' based titles as well. Like Pirate Empress, King of Dressrossa, Silver King, Four emperor etc.

For me, I see it as just a manifestation of extreme will, usually possessed by people with high levels of charisma and leadership abilities,.