Kaluu is a villain who first appeared in Strange Tales Vol.1 148.
Kaluu was born over five hundred years ago in Kamar-Taj, a small area in the Himalayan Mountains in the land now known as Tibet.
Kaluu and a youth now known only as the Ancient One became fellow students of the mystic arts.
Varnae, the eldest of the true vampires, met with Kaluu and imparted to him knowledge from the primeval compendium of black magic known as the Darkhold.
Subsequently, Kaluu set about to make himself ruler of Kamar-Taj. While the youth continued his studies, Kaluu used his sorcery to influence the minds of the people of Kamar-Taj.
Eventually, Kaluu and the youth together cast a spell that eliminated disease, poverty, and suffering from Kamar-Taj and granted its people immortality.
Shortly thereafter, the people of Kamar-Taj, responding to Kaluu's magical influence on their minds, crowned him as their king. For over a year Kaluu organized the men of Kamar-Taj into an army of conquest. (Kaluu has since claimed that he was only trying to bring a lasting peace to Kamar-Taj by making it so powerful none of the Asian conquerors of that time would dare attack it.)
Meanwhile, Kaluu slowly increased his mystic control over the minds of the people of Kamar-Taj so that they become little more than his placid puppets.
The youth attempted to warn the people of Kamar-Taj about Kaluu, but Kaluu's magic prevented them from heeding him.
Kaluu struck the youth with a magical bolt from behind which paralysed him. Then Kaluu had his soldiers conquer a neighbouring village and reduce it to slavery.
While Kaluu plotted further conquests and the people of Kamar-Taj fell into decadence, the paralysed youth, whom Kaluu had placed in the public square as an object of ridicule, mentally called upon mystical forces to defeat Kaluu.
However, the youth was not yet a master of the mystic arts, and, although he did not intend it, the mystic forces he summoned created a pestilence that wiped out virtually the entire population of Kamar-Taj.
Kaluu fled to the dimension of Raggadorr, where he remained for five centuries, increasing his mystical knowledge.
With Kaluu gone, the youth was freed from his paralysis. The population of Kamar-Taj, however, was no longer immortal, and the youth himself would now age, although at a greatly slowed rate.
The youth eventually became the sorcerer supreme of the Earth dimension known as the Ancient One.
In his final years he trained the disciple who would become his successor, Doctor Stephen Strange.
In the years just before the Ancient One’s death, Kaluu returned to Earth to destroy the Ancient One and to steal from him his greatest tome of mystical knowledge, the Book of the Vishanti.