The Zilart are one of the Enlightened Races in Final Fantasy XI. They appear similar to Humes, yet possess extremely high intelligence and magic potential, as well as a trait known as the "whisper of the soul", which is a combination of telepathy and mind reading. An offshoot of the Zilart formed without this trait, known as the Kuluu, and were treated as lesser beings by the Zilart.
For a time, the Zilarts were the only race who existed relatively peacefully, and this time is not well-documented. One of the Princes of the Zilartian King, Eald'narche, stumbled into a room of the mothercrystal and was presented with a vision of the realm beyond the Gate of the Gods and eternal paradise. Using the whisper of the soul, this vision was simultaneously presented to all of the Zilart throughout the world. Enchanted by this vision, they decided to build a path to open the Gate of the Gods.
The Gate was to be powered by the energy of Vana'diel's five Mothercrystals, channeled through giant power conduits to a central point at Delkfutt's Tower. They constructed a grand capital city named Tu'Lia, which is levitated into the sky by the channeling of the Mothercrystals' power. Tu'Lia was to be the gate, but at the moment of activation, the Kuluu sabotaged the Gate's power source, resulting in a cataclysmic meltdown that wiped out the land (known later as the Meltdown).
In this first expansion of Final Fantasy XI, two surviving Zilartian princes are revealed—the Jeunoan Archduke Kam'lanaut, and his elder brother Eald'narche. They continued attempts to open the Gate of the Gods, which is the focus of the Rise of the Zilart storyline.
In the game's second expansion, the Zilart are revealed to be alive and well, and a survivor of the Kuluu is also present.