Kingdom Hearts Ultimania originally launched in May 2004, following the earlier announcement of Kingdom Hearts 2 and KH: Chain of Memories in September 2003 at the Tokyo Game Show conference.
Initially, the website focused on being a comprehensive resource to follow the developments and updates on Kingdom Hearts 2 and the spin-off, KH: Chain of Memories for the Gameboy Advance.
Over time, the website picked up a reputation as being the first place to regularly publish the latest Kingdom Hearts series news, images and videos, complete with Japanese to English translations when necessary. In addition, the website provided and continues to cover every major video game conference including E3 and the Tokyo Game Show.
As time passed, the website expanded to consider the other developments and spin-offs in the Kingdom Hearts franchise, including the original Kingdom Hearts, KH: Coded, KH: 358/2 Days and Kingdom Hearts: Birth By Sleep.
Notable points during the websites beginnings include publishing the first images and videos from the English version of KH: Chain of Memories, reaching a peak of 80,000 visitors daily during the release of Kingdom Hearts 2.
In recent years, the website has progressively grew overall to be the largest resource for Information and Media content on the Kingdom Hearts Series.
To celebrate the launch of Kingdom Hearts: Birth By Sleep across North America, the fourth iteration of Kingdom Hearts Ultimania was brought online on September 7th, 2010.