The Celestials first appeared in The Eternals #1 in July 1976. They were conceived and brought to life by the legendary “King of Comics,” Jack Kirby, upon his return to Marvel Comics in the mid-1970s. Kirby, drawing from his fascination with ancient astronaut theories, Erich von Däniken's Chariots of the Gods?, and grand biblical epics, envisioned the Celestials as the ultimate expression of cosmic mystery and power. They were designed to be figures of awe and terror—silent, impossibly large, and visually distinct armored giants whose actions were as inscrutable as they were world-shattering. Kirby intended for The Eternals saga, and by extension the Celestials, to exist in its own separate continuity. However, following the series' cancellation and Kirby's departure, writers Roy Thomas and Mark Gruenwald integrated these cosmic beings into the mainstream Marvel Universe in Thor #283 (1979), establishing them as a foundational element of Marvel's cosmic lore, a status they have held ever since.
The origin of the Celestials is one of the most profound and frequently retconned mysteries in the Marvel Universe. What was once an unknowable truth has been expanded upon significantly, revealing a history tied to the very first iteration of reality.
The most recently established origin story traces the Celestials back to the very first universe, the First Firmament. This primordial, sentient universe was alone and desired companionship, so it created life: the dark and malleable Aspirants, and the brightly colored, diverse Celestials. The Celestials, unlike the sycophantic Aspirants who wished only to serve the First Firmament, believed that life should be allowed to evolve, change, and die—a concept their creator found abhorrent. This ideological schism led to a cataclysmic cosmic war. The Celestials created colossal armor and weapons, far beyond anything the Aspirants could conceive. The climax of this war was the deployment of a weapon so powerful that it shattered the First Firmament. The fractured pieces of this first reality coalesced into a new, revolutionary concept: the Multiverse. The core, surviving essence of the First Firmament was imprisoned outside the new Multiverse, plotting its revenge. The victorious Celestials became the progenitors of life as it is now known. They began their vast, cosmic-scale mission: to travel the Multiverse, find planets with the potential for life, and cultivate it. Their primary experiment involved creating three distinct genetic lines from the dominant species:
A pivotal, yet tragic, event in their early history involved a Celestial known as the Progenitor. Infected by the alien Horde while traveling through deep space, the Progenitor fell to Earth billions of years ago. Its death and decaying cosmic blood and flesh became a primordial soup that profoundly altered Earth's evolutionary trajectory, making it a unique hotbed for super-powered beings. It was the Progenitor's presence that later drew other Celestials to Earth for their “Hosts,” or judgment periods.
The MCU provides a more streamlined and concrete origin for the Celestials, as detailed primarily in the film Eternals (2021). Within this continuity, the Celestials are the first and oldest form of life in the universe. They are primordial beings who bring light, gravity, heat, and matter into existence, creating stars, galaxies, and eventually, life itself. Their purpose, as explained by the Prime Celestial, Arishem the Judge, is fundamentally tied to their own procreation. Celestials require immense amounts of energy to be born. To achieve this, they “seed” suitable planets with a Celestial embryo deep within the planetary core. They then populate the planet with life and create the Eternals—synthetic, programmed beings—to protect the burgeoning intelligent life from apex predators, specifically the Deviants (who were an earlier creation that went rogue and began preying on intelligent life instead of just predators). The Eternals' mission is to foster the growth of the planet's sentient population. Once the population reaches a certain threshold, the energy generated by their collective life force triggers the “Emergence.” This is the violent birth of the new Celestial, a process that completely consumes and destroys the host planet and its entire civilization. The energy from this one birth allows for the creation of billions of new worlds, continuing the cosmic cycle. Arishem and the others see this as a necessary, natural exchange: the destruction of one world for the creation of galaxies. This utilitarian and destructive purpose stands in stark contrast to the more mysterious, evolutionary-focused goal of their comic book counterparts.
The Celestials are defined by their incomprehensible scale, power, and inscrutable mission. While their appearance and abilities are broadly similar across continuities, their ultimate purpose differs significantly.
Celestials appear as colossal, silent, humanoid figures clad in impenetrable armor. Each Celestial has a unique design and title, reflecting their function (e.g., Arishem the Judge, Exitar the Exterminator, Gammenon the Gatherer). Their true form within the armor is a mystery, often described as pure, living energy or a “living universe.” Their average height is around 2,000 feet, but they can alter their size at will, with some like Exitar dwarfing entire planets. The armor is not merely protective; it is an instrument through which they channel and focus their cosmic energies.
The Celestials' power is nearly absolute, rivaling or exceeding that of other top-tier cosmic entities like Galactus or the abstract beings Eternity and Death.
The Celestials' primary interaction with Earth is through their periodic visits, known as the “Hosts.”
The MCU Celestials are visually similar to their comic counterparts—vast, armored beings with unique designs. However, their internal nature is shown more explicitly. They are living, biological beings with a metallic, armored exterior that appears to be part of their body. The birth of Tiamut from Earth's core showed a Celestial in its “raw” form, with hands and a head emerging from the planet's mantle. Knowhere, the severed head of a Celestial, is a biological location where organic material is mined. Their scale is immense, with Arishem being shown as large enough to dwarf planets.
Their powers are focused on creation and destruction on a galactic scale.
Unlike the comics' focus on evolutionary potential, the MCU Celestials' purpose is a clear, brutal cycle of procreation.
This mission is presented as a cosmic necessity, beyond good and evil. For Arishem, the sacrifice of one planet and its civilization is a small price to pay for the creation of new galaxies. This purpose is what the MCU's Eternals ultimately rebelled against, choosing to save humanity at the cost of Tiamut's birth.
Jack Kirby's original epic and its follow-up in the pages of Thor stand as the definitive Celestial story. When Arishem the Judge and the Fourth Host arrived on Earth, it was an extinction-level event. The story established their immense power by showing them effortlessly swatting away the combined might of Thor, the Eternals, and the Asgardian Destroyer armor. The conflict was not resolved through force, but by an appeal from Gaea, the spirit of Earth, who presented twelve of humanity's best as proof of their potential. This story cemented the Celestials as an unstoppable force of nature that cannot be fought, only reasoned with.
In the X-Factor comics, it was revealed that the Dreaming Celestial, Tiamut the Communicator, had been sealed beneath San Francisco. When he awoke, it was revealed that the Celestials were not just judging humanity's morality, but their genetic progress. The proliferation of mutants was a sign that their experiment was bearing fruit, and beings like Apocalypse and Mister Sinister spent their long lives trying to understand and control this Celestial-mandated evolution. This storyline fundamentally linked the Celestials to the entire X-Men mythos.
In Jason Aaron's Avengers run, the entire origin of superheroes on Earth was retconned to be a direct result of the fallen Progenitor. The arrival of the “Final Host,” a group of Dark Celestials infected by the Horde, forced a new team of Avengers to assemble. This story revealed that the first team of Avengers was a prehistoric group (led by Odin) that fought the maddened Progenitor when it first fell to Earth. The modern Avengers ultimately defeated the Final Host by uniting their powers and reanimating the corpse of the Progenitor as their own base of operations, now known as Avengers Mountain.
Perhaps the most radical re-imagining of the Celestials comes from the Earth X trilogy. In this reality, the Celestials are not “gardeners” of life, but cosmic midwives. Their true purpose is to protect planets that contain a Celestial embryo in their core. They manipulate the dominant species on the planet, giving them superpowers (in Earth's case, via the Terrigen Mists) to act as a planetary immune system, protecting the gestating Celestial within. It is revealed that Earth's embryo will one day be born as Galactus, who will then travel the cosmos consuming planets to prevent other Celestial embryos from hatching, thus preserving the universal balance. This brilliantly inverted the classic 616 dynamic.
The Celestials of the Ultimate Universe are significantly different and less prominent. They are not explicitly linked to the creation of mutants or other super-races. Their primary role is tied to the cosmic entity Gah Lak Tus, an intelligent, planet-devouring swarm of robots. The Celestials are portrayed as a rival alien race who created a doomsday weapon, the “Ultimate Nullifier,” to combat Gah Lak Tus.
As detailed extensively above, the MCU version represents the most significant mainstream adaptation. By giving them a clear, tangible, and destructive purpose (the Emergence), the MCU grounds their motivations in a way the comics deliberately avoid. This change makes them more direct antagonists for a film narrative, trading cosmic mystery for a more understandable, if terrifying, cosmic imperative.