Kamar-Taj, a hidden land high in the Himalayas, was populated by a race of people who, though not outwardly advance, had developed the arts of joyous living to a degree undreamed of by more complex civilizations. It was the birthplace of both Kaluu and the Ancient One. They grew to manhood there, among gentle folk who knew not the meaning of war, whose lives were as free and bright as the laughter of their children. They tilled the Earth, and took their pleasure in the eternal pageantry of nature.
Yet, Kaluu and the Ancient One did not choose to live as their brothers. Together, they plumbed the secrets of the supernatural. And together they discovered the means of harnessing mystic energies for their own use. They stood on the threshhold of ultimate power. With the spells they had recorded on parchments, there would be nothing they could not accomplish. The Ancient One originally wanted to use their power to benefit the people, but Kaluu had bigger plans. Instead of helping the people, he wanted domination.
While the Ancient One remained engrossed in his arcane studies, Kaluu used his knowledge of psychic hypnosis to slowly gain control over the minds of the people. Many months they kept their chamber, refining mysterious knowledge they had gained, until one day, Kaluu approached the Ancient One, his eyes glittering. He said it was time to summon their destiny. Stepping onto a balcony which overlooked the silent village, they invoked all the hidden forces of the super-natural, casting an enchantment over the land. For an instant, the very ground beneath their feet shuddered, as their spell gripped all nature.
Then, it seemed the sun itself shone more brightly, and the air was sweet in their nostrils. Disease, poverty, and pain vanished, and for the first time in the long history of mankind, human beings were free to exist in perfect happiness. Intoxicated with their success, Kaluu and the Ancient One walked through the village. Then, the people had to choose a ruler. Though the Ancient one had been a faithful companion, Kaluu insisted that he refuse the throne. For, only Kaluu felt he had the courage and strength to lead. Kaluu did not realize that the Ancient One knows what he has done - that he implanted within the people the desire to crown him king. The Ancient One gave Kaluu sway - but he stayed near him, that he may oppose his plans for conquest.
And so, at the council of the elders, Kaluu was honored above all other men. Kaluu was made king. But within hours after his coronation, he began to transform the farmers into warriors - mere armed pawns in the service of his unquenchable ambition. The Ancient One was unable to convince the people of their danger. Again and again he gave warnings, but to no avail. Kaluu's hypnotic prowess had made the people's ears deaf to any voice but his. Their village prospered as no others ever had. The people were never sick - their fields yielded plentifully, their cattle multiplied beyond all expectation. For more than a year after Kaluu and the Ancient One cast their spell they heard not the sound of crying, nor saw on the villagers' faces any expression save a gentle smile. Thus, even from such a reign of evil, there came good. But, at what price - that the people became no more than the puppets of Kaluu. His word was never questioned, and his every pronouncement was accepted as truth. Only the Ancient one had begun to worry, for every night he saw Kaluu conjure in his crystal the image of the settlement at the foot of the mountain.
Kaluu saw his neighbors prosper. Their barns were full. If Kaluu could but conquer them, his own people could devote all their skills to the practice of warfare. The crystal showed him that their neighbors had no army - no weapons. Then on the following morning in the public square, Kaluu addressed the village of his plan.
In modern times, Kaluu once tried to steal the Book of the Vishanti from the Ancient One and Dr. Strange. It took both of them to defeat him.
Later on, Kaluu visited Dr. Strange when Strange had fallen upon bad times. Strange had had to destroy all his artifacts of power, including the Book of the Vishanti, in order to stop Urthona. Since he was now so weak, he had to start using Black Magic, and was too too impure to use the Eye of Agamotto any more. However, many demons and evil spirits were invading our plane of existence, since they were no longer held back by his artifacts. Kaluu came to Strange and told him that he would take Strange on as a disciple and teach him how to truly use Black Magic in order to protect our plane. At first Strange resisted, knowing Kaluu's past. However, Kaluu said that while he had done evil, he had done so to help his people. The Ancient One had told Strange that Kaluu brought his people to a level of lushness and opulence. However, Kaluu said that this was a barbaric time, and the opulence that his people enjoyed was getting to eat meat once a year, and have some peppercorn--he was hardly a Nero. Strange eventually agreed to work with him, and together they managed to defeat a series of demons, finally including Shuma-Gorath.
Kaluu is a Black magician of great power. He learned side by side with the Ancient One, although they had different practices and areas of focus. He was knowledgeable enough in the ways of magic to teach Dr. Strange new magic and new approaches, enabling them both to take on very formidable demons.