The Inhumans are a race of beings who diverged from mainstream humanity twenty-five thousand years ago as a result of genetic experimentation on primitive man performed by the alien Kree. The Kree had been frequent visitors to Earth's solar system, ever since the alien Skrulls deposited a handful of Kree scientists on Earth's moon in a contest to determine whether to award the Kree the secrets of Skrull technology. The Kree scientists built the Blue City on the moon, and after seizing certain technologies from the Skrulls, left robotic Sentries on Earth, the moon, and Uranus.

Millennia after the vastly powerful alien Celestials had performed experiments on primitive man to create the subspecies of humanity called the Eternals, the Eternals engaged in civil war. The leaders of the vanquished side were exiled into space and happened upon the Kree weapons depot on Uranus. The exiled Eternals fought and destroyed the Kree Sentry posted there, which activated a transgalactic alarm. Believing the destruction to be the handiwork of their enemies the Skrulls, a Kree armada investigated the incident only to discover the Eternals as the culprits. A vivisection of one of the Eternals revealed to the Kree that he was a highly evolved human being.

The Kree scientists then petitioned their rulers to be allowed to perform their own experiments on human stock in order to create a race of superhuman warriors to serve the Kree. Returning to Earth, the scientists eventually succeeded in fashioning a small tribe of highly genetically advanced human beings. However, the Kree abandoned their plan to make immediate use of the fledgling race, for reasons as yet undiscovered. This race of beings would someday be known as the lnhumans.

After the Kree left them, the Inhumans wandered the Eurasian continent until they decided to settle upon a tiny island in the Northern Atlantic, which they named Attilan. There they began to develop technology and culture at an even faster rate than their more powerful predecessors, the Eternals. Chief among their scientific disciplines was genetics, and the lnhumans set up a government based on genocracy, rule by the genetically fittest. Some four thousand years later, mainstream humanity built its first great civilization on the island continent of Atlantis. The Inhumans made every effort to remain isolated from the expanding Atlantean empire, but there must have been some interaction between the peoples to judge by the etymological similarity between the words Atlantis and Attilan. How the Inhumans managed to remain isolated from the Atianteans is not yet known.

Presumably the Inhumans used their superior technology to resist attempts at assimilation. When the continent of Atlantis underwent geothermic upheaval and sank beneath the sea, Attilan somehow protected itself from the cataclysm, again possibly using technology. Sometime within the Inhumans' first millennium of existence, the Inhuman geneticist Randac isolated a chemical catalyst for human mutation, a substance he called Terrigen. Believing the substance to be the key to making great genetic advances within a single generation's time, Randac subjected himself to total immersion in the Terrigen Mist and emerged with mental-manipulative powers rivaling those of the Eternals. Elected ruler because of his genetic superiority, Randac unselfishly instituted a program by which all Inhumans could undergo Terrigen treatment if they desired.

The program was halted when about half of the Terrigen subjects developed radically non-human mutations. It was thereafter decided that individuals would only undergo treatment after being thoroughly genetically tested, but the damage to the gene pool was already done. Centuries later, an Inhuman leader named Gral, tired of the discrimination against the non-human-looking minority, instituted a reign of terror in which the entire population of Attilan was involuntarily subjected to the mutagenic Terrigen Mist. The Mist transformed over three-quarters of the population into non-humanoid types, altering their genetic destinies for untold generations. Successive exposure to the Terrigen only furthered the extent of the mutation. For years, the Inhumans were segregated into Mutation Camps, forced to live only among their own basic phenotypes. Finally, Gral was deposed, and an Inhuman named Auran taught his fellows how to accept the wonderful diversities of their people in peace.

This era came to an end about 2,500 years ago, when a contingent of winged Inhumans built their own city suspended high above Attilan. Antagonism between the sky- and ground-dwellers eventually led to the secession of the sky-city from Attilan proper. The small colony of winged Inhumans existed in relative peace until the early part of the Twentieth Century when the race was inadvertently destroyed by a human being they called Red Raven.

Over the millennia, Inhuman geneticists have tried to stabilize the diversity of their genetic heritage. Unlike Earth's other genetically variant race, the Deviants, whose offspring tend to inherit none of their parents' genetic traits, Inhuman infants tend to resemble their parents. Thus if an Inhuman with amphibian characteristics mated with an Inhuman with avian characteristics, their offspring would have a combination of these traits. This, however, seldom occurs since, until recent times, marriages have been arranged by the government to eugenically further the race. At present, rigorous eugenic control has succeeded in restoring about a quarter of the Mutation Camp victims' descendants to human-looking normalcy. Slightly less than half of the present population of Attilan has a visible non-humanoid mutation. About four thousand years ago, an Inhuman named Avadar convinced the Council of Genetics to lift their ban on cloning experimentation so that he could genetically design a sub-human drone capable of performing all of the menial labors necessary to society.

The Council agreed, and Avadar produced a line of worker-clones called the Alpha Primitives. It has only been in recent times that the practice of cloning new slave laborers has ceased. Since the time of Randac, the government of the Inhumans has consisted of the twelve-member Genetic Council, which is the major legislative, judicial, and executive body. Each Council member belongs to a different family or House, and is elected to membership by the other members of the Council. Membership in the Genetics Council is for life (unless the member commits a crime against the state and is expelled).

Consequently membership changes in the Council only when there is a vacancy due to death. The Council elects one of its members as both head of the Council and ruler (or "king") of the Inhumans. This ruler customarily reigns from election to his or her death (again barring dishonorable removal). It takes all eleven other members of the Genetics Council to remove a ruler from the throne. Kingship then does not follow a strict patriarchal or matriarchal progression, although popular rulers are often succeeded by their sons or daughters. The designation "Royal Family" is a ceremonial one that is passed on from House to House with successive kings. About 110 years ago, an Inhuman named Agon was elected to the Genetics Council, and subsequently to rulership over the Inhumans. Agon proved to be one of the most popular rulers since Auran.

A skilled geneticist, Agon made significant advances in the prediction of Terrigen effects on the Inhuman gene, and convinced his wife Rynda to subject herself to the Terrigen Mist while pregnant. Their son Blackagar (popularly called Black Bolt) became the most powerful Inhuman in the race's history, surpassing the powers of Randac himself (see Black Bolt). Agon and Rynda persuaded their brothers and sisters to also subject heir children to the mist in utero, and each of their offspring was born with a different superhuman ability or mutation. Agon was a decisive ruler, and when he caught a Council member named Phaeder experimenting with clones, he persuaded the Council to have him expelled.

Phaeder protested that it was anti-scientific to restrict cloning to the perpetuation of the Alpha Primitives, but Agan prevailed. Faking his own suicide with a clone of himself, Phaeder left Attilan and eventually bore a son to an as yet unknown woman. The son was named Maelstrom, and later became a dangerous enemy of Attilan as well as a purveyor of Attilan's most guarded secret, Terrigen. About ninety years into Agon's reign, the Kree finally renewed their interest in recruiting the Inhumans for their war effort. Agon's second son, the sinister Maximus, entered into secret negotiations with emissaries of the Kree. When Maximus's brother, Black Bolt discovered the treacherous liaison, he used his quasi-sonic powers to blast the Kree spy-ship out of the sky. The damaged ship fell to the Earth, crashing into the laboratory where Agon and Rynda were working. They were killed instantly. Because Agon was such a popular leader, Black Bolt was elected to the Genetics Council to succeed him, and despite his silent protests was soon crowned the new ruler of Attilan. Black Bolt's rule has been the most tumultuous in the Inhumans' history. Within a year after ascending the throne, Black Bolt was faced with the probable discovery of Attilan by the outside world. To solve this problem, Black Bolt scouted out a new location for the island and found one in the remote Himalayan Mountains of Tibet. While searching for the new site, Black Bolt encountered Ikaris of the Eternals. The Eternals helped excavate the pit that would be Attilan's new foundation. Black Bolt then returned to Attilan and manufactured anti-gravity generators based on those that kept the floating city aloft millennia before. After digging out the base of the island and mounting the anti-gravity generators underneath, the entire island was moved from the mid-Atlantic to the Himalayas. Shortly thereafter, Black Bolt's kingship was challenged by his brother Maximus.

With the aid of three transformed Alpha Primitives called the Trikon, Maximus sparked Attilan's first civil war in millennia, a war that succeeded in driving Black Bolt from the throne and into forced exile. For almost a decade, Black Bolt and his loyal cousins wandered Asia, Europe, and finally America. When they finally returned to Attilan, Black Bolt wrested the crown once more from Maximus. Maximus tried to regain the crown from Black Bolt on subsequent occasions, but was never as successful as he had been in his initial attempt. On the second of these attempts, Maximus manacled Black Bolt and deprived him of food or water for close to a week, while forcing half the Inhuman populace to board an ark to deliver them to the Kree. In this abject state, Black Bolt misjudged his power and in an attempt to destroy the ark, leveled the entire city of Attilan. It was later rebuilt with a totally different style of architecture. Black Bolt was also obliged to relocate the Inhumans' home for the second time in less than half a century. The debilitating effects of Earth's pollution caused a great plague to sweep through Attilan, and in order to save his people, Black Bolt once again used the anti-gravity generators to move the entire island. This time Attilan was moved off Earth entirely, to the Blue City on the moon.

Ironically, the Blue City is a product of the Kree, as are the lnhumans themselves. The Blue City retains a germ-free oxygen-rich atmosphere, and the anti-gravity generators have been adjusted to create a normal Earth-like gravity beneath Attilan. Although certain radar systems, satellites, and intelligence agencies detected Attilan's exodus, the general public of Earth was unaware of the event. The general public is aware of the existence of the Inhuman race, although few human beings outside the Fantastic Four and Avengers have ever been to Attilan. At present there are about 1,230 living Inhumans, all of who dwell in Attilan. By stringent governmental restriction, the lnhumans practice zero population growth, allowing couples to bear a maximum of two offspring. The government also has strict laws regulating Terrigen Mist exposure. Couples must undergo strict genetic testing before their offspring are permitted to be exposed to the Mist. Exposure of infants in utero is only permitted if the mother has not already been previously exposed to the Terrigen Mist. If the genetic screening determines a low risk factor, a couple may elect to subject their child to the Mist between one and six years of age. If an individual did not become exposed to the Mist when a child, he or she has the right to choose to take the treatment when he or she reaches 13, the legal age of consent.

Recent statistics show that less than half of the children born are Terrigenated and only about one tenth of the non-exposed adults choose to undergo the process at 31. At present only about half of the Inhuman population possesses obvious non-human characteristics either through heredity or Terrigen mutation. Inhumans speak their own language, Tilan, but in recent years, many have elected to learn such human languages as English, Russian, and Chinese. The Inhumans have various trade guilds managing the various disciplines necessary to maintain society. Almost three-fourths of all lnhumans elect to go into their parents' professions. Food is cultivated in hydroponic gardens beneath the city.

The chief pursuit of the people is science, but they also have various artists' guilds, including a theatrical company which provides circus-like entertainment's as well as a cycle of plays based on famous incidents in Inhuman history. The major religion of the lnhumans involves ancestor-worship and there is a guild of priests and priestesses who administer the faith. Attilan has traditionally had a small police force and perimeter patrol, which, under Black Bolt's rule, expanded into a small militia of about 50 specially trained soldiers. Since Attilan has never been at war with any other country, the militia is customarily used as an internal peacekeeping force. Attilan has one prison and the king of Attilan serves as its sole judge. Despite the diversity of its citizenry, Inhuman society remains relatively stable, homogenous, and austere.