The Kree is an extraterrestrial humanoid race who have created a vast empire in the Greater Magellanic Cloud. The Kree race began on the planet Hala in the Pama system long before the first mammals appeared on Earth. The original Kree had blue-colored skin, but a second racial group with pink skin resembling that of human caucasians emerged over the millennia. At present, the blue-skinned "purebred" Kree are a small but powerful minority. Outwardly humanoid to a large degree, Kree bodies are adapted to environmental characteristics on Hala that are un-Earthlike: notably, higher gravity and a higher nitrogen content in the atmosphere. Although the Kree cannot breathe Earth's atmosphere without special apparatus, their denser bodies afford them about twice the average human being's strength and endurance. Despite their physical superiority and relatively advanced technology, the Kree race has reached the pinnacle of their evolutionary development, having not significantly changed in any way in tens of thousands of years.

The Kree Empire extends across almost a thousand worlds in the northwestern lobe (Earth reference) of the Greater Magellanic Cloud. The Kree began their empire over a million years ago, within a hundred years of the acquisition of interstellar technology from the then-benevolent race of Skrulls. The Skrulls at the time were attempting to foster a galactic empire based on free trade, and they landed on Hala to help the barbaric natives advance to the point where they could join. Finding that Hala boasted two equally intelligent lifeforms, the humanoid Kree and the plant-like Cotati, the Skrulls proposed a test to determine the worthier race. The Skrulls took an equal number of Kree and Cotati to a distant planetoid in another galaxy, Earth's moon, and fashioning an artificial atmosphere in which to work, bid the two groups to use their resources to create something of worth of the barren world. The Skrulls then departed. The Kree set about constructing a magnificent industrial city. The Cotati produced saplings and grew an equally magnificent garden. A year later (Earth reckoning), the Skrulls returned and judged the Cotati's achievement worthier. Enraged, the Kree leader Morag incited his fellows to slay the Skrulls and the Cotati and seize the Skrullian starship and its attendant technology. Mastering it within two generations, the Kree launched an attack on the Skrull Empire, and led the once-peaceful Skrulls to become increasingly militaristic to repulse them. Thus the Kree-Skrull War began; a conflict that would last thousands of years. (The Earth's Watcher Uatu took possession of the Blue City on the moon as soon as the Kree abandoned it.)

Though Hala is the planet of the Kree's origin, the planet Kree-Lar in the Turunal system is the capital of the Kree Empire as well as the seat of the government. The Kree Empire is ruled as a militaristic dictatorship. The permanent ruler is the organic computer-construct called the Supremor (or Supreme Intelligence), an immense computer system to which the preserved brains of the greatest intellects of the Kree race have been linked. Aiding the Supreme Intelligence is a number of imperial administrators on Kree-Lar, appointed governors of each of the memberworlds, and a vast standing space militia. The empire also employs powerful automatons called Sentries to keep member-worlds under surveillance.

Although Earth is in a different galaxy from the Kree Empire, the Kree have been aware of Earth for eons, since it is near a natural space-warp access-point shown to them by the Skrulls. When the Kree-Skrull War began, the Kree built a supply outpost on the planet Uranus, hoping to maintain a weapons base close to this strategic sight. Soon after the human race began, the Kree learned of humanity's vast genetic potential. Several hundred years before, the star spanning Celestials had visited Earth and artificially evolved the advanced Eternal and Deviant sub-species. When a small group of Eternals were exiled from Earth, they happened upon the Kree outpost on Uranus, defeated the Sentry, and raided the supply depot for the means to return to Earth. The Kree, believing that the Skrulls had discovered the outpost, sent an armada which overtook the crude spaceship fashioned by the Eternals to return to Earth. Destroying it, the Kree took an Eternal alive for study. Kree scientists vivisected him and learned that he was human in genetic origin. These scientists petitioned their leaders to allow them to travel to Earth in order to perform their own experiments on the native human beings. The Supreme Intelligence granted them permission, hoping they might develop a breed of super-soldiers to aid the Kree in their war effort against the Skrulls. The Kree scientists experimented on nascent humanity and created the highly-evolved sub-species that would one day be called the Inhumans. For unknown reasons, the Kree administration dropped their immediate plans to use the Inhumans as militia, although they would millennia later attempt to do so. The Kree did deposit a Sentry on Earth to monitor the Inhumans' progress and possible Skrull activity.

Despite frequent surveillance, the official policy of the Kree government is that Earth is a minor, limited-potential planet of little importance. The upper echelons are aware of the truth, however: not only is Earth in a strategic military position, but its denizens possess the genetic potential to be a serious threat to the already decaying Kree Empire and race. Mainstream humanity first became aware of the Kree when archaeologist Daniel Damien discovered the South Pacific Island outpost of the Kree Sentry 459. The Fantastic Four happened by and battled the Sentry. Learning that its Sentry had been tampered with, the Supreme Intelligence dispatched Ronan the Public Accuser to Earth to punish the perpetrators. The Fantastic Four, however, managed to repulse him. Now aware that the Earth boasted very capable defenders, the Kree sent a lone starship, the Hala, whose commanding officers were Colonel Yon-Rogg and Captain Mar-Vell, to monitor the Earth and conduct a feasibility study for its invasion. Mar-Vell, a Kree military here, eventually defected to the side of the Earth, and became known as Captain Marvel I. Despite Mar-Vell's defection, the Supreme Intelligence formulated a plan to revitalize the Kree's genetic potential by bending Mar-Vell to the Earthman Rick Jones. The Kree never launched an invasion on Earth, although a skirmish in the eons-old Kree-Skrull War did occur in Earth's solar system, and involved over a dozen of Earth's superhuman champions, notably the Avengers. In recent decades, the Kree have tried to recruit the Inhumans as soldiers three times. The plans the Supreme Intelligence had for Mar-Vell evaporated with Mar-Vell's death, and the Supreme Intelligence itself has twice been deposed from rulership by its ambitious administrators, Ronan and Zarek. The Supreme Intelligence is currently again in power.

The Kree are a highly regimented, militaristic society. Little else is known about their culture. The official state religion worships the Supreme Intelligence, although the government has permitted adherents to the Universal Church of Truth to erect temples throughout the empire, including on Kree-Lar. There are also secret sects of Cotati worshippers. The Kree Empire's technology remains hundreds of years ahead of Earth's, but has not had any significant advances in millennia. The Kree Empire, like the Kree race itself, is old and moribund. The Supreme Intelligence's rule has been conservative and relatively unimaginative. It remains to be seen how long it will take before the empire begins to crumble.

First Appearance: (mentioned) FANTASTIC FOUR #64, FANTASTIC FOUR #65.