Introduction
In Eternals (5th series) all Eternals are now said to have been created at the same time. For the Eternals such as Mentor, Thena, Zuras etc. this means their familial relationships are "performative", but also genetically ingrained in their Eternal status. Many of the stories involving the Eternals favour a “story-over-continuity” approach as such the material has been prone to inconsistencies. There is also the revelations from Eternals (3rd series) that Sprite was manipulating the race's collective memories for nearly a century, and other material from Eternals (5th series) showing they deliberately modify their racial memories at times. It should be understood that some of the below information may be classed as “mythos" and therefore subject to change to a level that would exceed other Marvel franchises.
Early Origins
The Eternals were created by the race of “space gods” known as the Celestials. The Celestials had selected a tribe of early apes, called the Wanderers, to experiment on creating the three basic Terran races, the Eternals, the Deviants and also sowing the building blocks for what would become modern humans / mutants. [Uncanny X-Men Annual (1st series) #13]
The Eternals were far more advanced than their peers and founded a closed society in their first city known as Titanos. Like even “lesser” beings, they were not above conflict and a civil war broke out between the followers of two brothers, Chronos / Kronos (who wished to protect humanity) and his brother Uranos (who wished to enslave them). Chronos prevailed and exiled his brother and his followers from Earth. Uranos and his faction found themselves on the planet Uranus. Taking control of an old Kree outpost, they started to build a fleet to return to the home-world and take it by force. These exiles soon split along ideological lines, with some opting to remain at the outpost under the leadership of another Eternal named Astron and rest following Uranos back to Earth. Unfortunately for them, Uranos' fleet was intercepted and destroyed by the Kree in retaliation for attacking their outpost. The survivors fled to the moon of Titan, feeling they had a lucky escape, and opted to build a new society in the bowels of the planet. [What If..? (1st series) #26-28]
Modern retellings of this first schism show that Uranos didn't simply want to enslave other races, but rather intended "omni-genocide". Uranite teachings were to obey the letter of the Three Laws (Protect the Machine of Earth, Protect Celestials, Correct Excess Deviation), but in fact to eradicate all life on the planet before turning it into a mobile dreadnaught to bring genocide to the stars. The real Uranos was held in Exclusion for fear of his dead man's switch igniting his arsenals. The Uranites crafted a half-baked clone of Uranos to lead them before their departure, not the original. [Eternals: The Heretic #1]
With the exception of Sui-San, all Uranites on Uranos and Titan eventually perished and returned to the Machine. Instead of permanent Exclusion, they joined the Oceanic Watch as penance. [Eternals: Thanos Rising #1] Uranos and Kronos had a third brother, Oceanus. As one of the three Patriarchs, Oceanus presumably has children and grandchildren among the 100 Eternals who have not been identified. Oceanus fought alongside Kronos during the Uranite Schism, but ultimately feared his own dark impulses and stepped back from any leadership role among his people. This ended the era of the Patriarchs and began the period of the Eternals being led by a single Prime Eternal, starting with Kronos. Oceanus founded the Oceanic Watch as soldiers held in reserve to keep watch on Deviant Lemuria for uprisings by the Eternals' enemies. He and Uranos's former followers would serve as weapons to follow the Prime Eternals orders, instead of making decisions on their own again. [Eternals: The Heretic #1]
During an experiment gone awry, Chronos destroyed his corporeal body and merged with the Firmament of the universe. Due to his strong will, however, he was still able to manifest himself on occasion. In his absence, Chronos’ sons Zuras and A'Lars contended for role of Prime Eternal. The Uni-Mind decided to follow Zuras's lead, and so A'Lars exiled himself into deep space rather than remain on Earth as a visible threat to Zuras's authority. A'Lars wandered the universe for some time and eventually came across his uncle's colony. By the time he discovered it, however, the colony had been destroyed with only one survivor, a woman named Sui-San. A'lars married Sui-San and the two began to rebuild Titan using a mixture of genetic engineering and cloning. On this new world, he took on a new name, Mentor. [Captain Marvel (1st series) #29, Eternals (5th series) #1-2]
[Note: In Eternals (5th series) it is said that Kronos' experiment actually resulted in the birth of a space god and was not his own personal ascension. In practice, it seems that Kronos physically "died" during his ascension and was therefore subject to resurrection. However, he was kept in Exclusion for the crime of "autonomous auto-deification" so that a second Kronos did not contradict or invalidate the separate existence of Kronos as an abstract being.]
Modern retellings show an actual war broke out between the followers of Zuras and A'Lars, the second major schism in the Eternals. The Celestials created 100 Eternals for the Great Machine, leaving the race static and unable to truly reproduce. Eternals could have children with other races, sometimes appearing normal and sometimes manifesting as super-powered hybrids. However, these "Nephilites" were not "True" Eternals integrated into the Great Machine, the Three Laws, Resurrection, etc. A'Lars wished to conduct genetic experiments to expand the Eternal race, while Zuras thought it foolish or possibly heresy to even try. Their mother Daina, wife of Kronos, orchestrated a truce where A'Lars would go into exile to determine if his experiments were even possible, then submit his findings for the accord. In order to quell grudges from the war and streamline the new narrative, a full reboot of the Eternals line was conducted to alter the race's memories. Many Eternals forgot even which side they were on for the schism, and this may also explain older contradictory reports that a known pacifist like A'Lars was exiled for being too warlike, akin to his uncle Uranos. [Eternals: Thanos Rising #1]
The Line of Zuras
Zuras married his fellow Eternal, Cybele (named after the Phrygian mother goddess) and they have one daughter, Azura, later renamed after the Greek goddess of war, Athena. While an excellent warrior and commander, Thena has differed from her virginal namesake as she has had a rather rich love life.
Thena met arguably the love of her life, the Deviant warrior Kro, approximately 2,500 years ago. The two fought in ancient Babylon with Kro gaining the upper hand. Seeing Thena up close, Kro was struck by his enemy's beauty. Instantly smitten he surrendered his advantage and laid down arms. Luckily for him, his change of heart was reciprocal on Thena's end too. The pair briefly spent some time together before returning to their people, seeing no future as a couple due to their races' enmity for each other. Unlike other members of his species, Kro is very long lived, the result of genetic mutation, and may in fact be immortal. Thena reunited with Kro by chance in another battle field during the Vietnam War. Despite the fact that their relationship was still considered miscegenation and a betrayal by their societies by the modern age, Thena and Kro found themselves impossibly drawn to each other. The romance resulted in Thena becoming pregnant with twins. To hide her transgression, Thena found a sterile human woman in California named Mrs. Ritter and transferred her pregnancy to her, allowing her twins to grow up to adulthood in relative ambiguity. Given their pedigreed nature, the twins, Deborah and Donald Ritter, were eventually sought out by enemies of their parents and nearly killed just before they reached their eighteenth birthday. Fortunately, they were saved by their mother (who had been secretly keeping tabs on them since birth) and her fellow Eternals. Thena told the children their true identities and introduced them to their father, who had been unaware of their existence.
In addition to their mother's optic blasts, the twins have displayed the unusual ability to fuse together into a super-powered form. So far, the twins have shown the ability to merge into two distinct combined forms with seemingly different power-sets (both visible in above family tree graphic). For example, as “Tzabaoth,” the twins didn't display flight, as they did as “Dark Angel.” The twins have also inherited their parents’ heroic natures and have fought alongside both of them, with Thena and her allies in the Heroes for Hire and Kro and his deviant super hero team Delta Force and Earth's mightiest heroes the Avengers. [Eternals: Herod Factor #1, Avengers (1st series) #370-371, Heroes for Hire (1st series) #6-7]
Due to the machinations of the mischievous Eternal called Sprite, several Eternals temporarily lost their memories, including Thena. This gave her a second chance at motherhood. 
Thena married a mortal man, an editor/novelist named Thomas Elliot, with the two having a son named Joey. How long exactly Thena's marriage to Thomas lasted is unclear but he was killed when he accidentally stumbled across a group of terrorists. In the aftermath of his death and upon the return of her memories, Thena refused to return Joey to the mortal world and he remained in her care in the current Eternal capital Olympia as her son. Initially, Joey was depicted as distinctly Asian and it was assumed that Thena was not his biological mother, as Thomas and Thena have both depicted as Caucasian. Joey was also repeatedly referred to as “human” by the other Eternals. Later stories have confused this, as other artists have depicted Joey as Caucasian and Thena's father Zuras has referred to Joey as his “blood” in Eternals (3rd series) #4. Further, in an alternate reality featured at the end of Eternals (3rd series), Joey was shown in the year 2115 AD very much alive in his prime and in possession of similar abilities of the Eternals (flight and mind control), leaving his heritage ambiguous. [Eternals (3rd series) #1-7, Eternals (4th series) #1-9] Joey's current whereabouts are unknown as of Eternals (5th series).
The Line of Mentor
Fate was not as kind to A'lars (Mentor) as it was to his brother Zuras. Sui-San had two sons by Mentor. One was Eros (later known as Starfox), who became a hero and an on and off again member of the Avengers. The other boy was Thanos, who would bring blight to their family and the known universe. Originally, Sui-San intended to call her unborn baby Dione. When the child was born deformed, afflicted by the Deviant syndrome, Sui-San saw only death in his eyes and attempted to stab him. She was stopped by her husband A'Lars, who conversely could only see good in their baby, now named Thanos. Sui-San was institutionalized shortly thereafter and remained in an asylum for many years.
[Note: Some sources have claimed that Eros is the younger sibling but as Sui-San was shown to have suffered a breakdown following Thanos' birth, this seems unlikely.]
Mentor was also depicted as having another wife called Kazantra in Daredevil (1st series) #105 at a period in which Thanos and Eros were very young children. The existence of Kazantra does not make sense, as we have seen Sui-San remained in the family up until Thanos' teens in Thanos Rising. A few scenarios explain Sui-San:
- Mentor was polygamous and had multiple wives.
- Kazantra was actually Sui-San: The depiction of Sui-San has changed numerous times over the years, initially debuting as a brown-skinned woman with reddish brown hair, to a redhead with Caucasian complexion, to a black haired Caucasian woman and finally a dark haired woman with Asian features in Thanos Rising. While the inconsistencies are likely artist/editorial error, Eternals do have the ability to change their appearance and some have on occasion gone by different names. Sui- San's mental instability could be responsible for her shifting appearances and even use of a different name in a short time period.
The young Thanos had been noticed by the personification of Death. Taking on the appearance of a classmate, Death began to groom Thanos, seeing his potential for destruction. Regardless of his poor start, Thanos was actually accepted by his peers, his genetic mutation giving him some degree of “celebrity” in the homogenized Titan society. However, he remained traumatized by his mother's attempted murder of him. The incident tormented him in his nightmares, so he made the decision to stop dreaming. His father failed to show sufficient attention, burying his head in the sand, focusing on his scientific career and in turn did not notice that his son was troubled. When a young Thanos failed to dissect a lizard in class, Death told him of a cave with beautiful rock formations. Thanos took some of his frien
ds to the caves but the tunnel collapsed, separating them. Several days passed before Thanos managed to dig his way out, finding the bodies of his friends devoured by the breed of lizard he had refused to dissect. The disturbing incident started to isolate Thanos from his peers. Feeding this rage, Death guided him back to the cave some time later, where he slaughtered every lizard he could find.
As Thanos entered his teens, his murders escalated with the dissection of larger prey. Death continued her masquerade of posing as a peer in Thanos' life as “they” both entered their teens. Thanos remained totally fixated on her and made his intentions towards her clear but she rejected him. This, by design, only fed his growing rage. That anger only made him more pliable to her suggestion as she encouraged him to capture other members of his species for experimentation. After murdering 17 people, Thanos finally abducted his own mother, hoping to “find answers in her body” as to what was wrong with him.
[Note: In Captain Marvel (1st series) #33, it was mentioned that Thanos had been exiled for the crime of creating a weapon by his father Mentor. It was also stated that Sui-San died in an attack of Titan by Thanos. It can be assumed that Thanos Rising effectively retcons both these stories.]
Following the vivisection of his mother, Thanos fled Titan. Hoping to fill the void that was inside him, he murdered and slept his way across the known universe, siring an untold number of children with women from different alien species. Irrationally, despite his own seed “breeding strong,” Thanos believed his children did not resemble him, only their mothers. Feeling homesick, he returned to Titan and met Death, still unaware of her true identity. She offered her hand in marriage if he would kill the children so he would be only hers. Already obsessed with her and desperate for her love, Thanos sought to honor her request and began hunting down his own offspring and their mothers, murdering them all with no hesitation or remorse. The murder of his own kin did not provide sufficient succor for Death and she prodded Thanos to escalate his rampage, culminating in the slaughter of whole worlds. Finally revealing her identity to him, she goaded him to destroy Titan itself, promising to love him forever. Thanos initially attempted suicide but his desperation for her made him agree to her latest abominable request and he instructed his fleet to travel to Titan.
Thanos laid siege to his home world, killing most of its inhabitants. Walking upon the scorched surface, Thanos encountered his father Mentor. Mentor had fashioned a weapon, hoping to kill his son. Despite everything that had happened, in the final moment, Mentor still could not bring himself to kill his own son. Thanos told his father that he would dispose of him after his wedding, much to Mentor's confusion, as he believed there was no one left alive for Thanos to marry. Thanos explained that he was going to marry Death, his only companion. Mentor attempted to reason with Thanos, believing Death to be a mere figment of his imagination but to no avail. After this exchange and implantation of some doubt from Mentor's words, Thanos decided to leave his father alive on Titan to bear witness to the destruction that he would bring to the galaxy. [Thanos Rising #3-5]
[Note: During one of his many deaths, Thanos did finally gain Death's “embrace.” The coming together of two such destructive beings created the “Rot.” Not a person per se, the “Rot” was the absence of life or death and was seemingly destroyed by Death and one of the many duplicates of Thanos. More on them later. [Avengers: Celestial Quest #1-8]
Despite all the turmoil and destruction that Thanos has brought the universe, he and Eros continued to honor a request of Mentor's from their childhood and once a year they end hostilities and exchange gifts as part of an event they call “the truce.” [Quasar #59]
The Children of Thanos
Thanos' belief that he had managed to wipe out his own line was actually false.
One woman who has claimed descent from Thanos, much to his chagrin, is the space pirate and mercenary, Nebula. Several accounts have been presented by Nebula regarding her origin and it is possible none are true.
- She was the daughter of a blue skinned son of Thanos, who was sexually abusive towards her before she finally murdered him when she reached her teens. [Silver Surfer Annual (3rd series) #5]
- She was the daughter of the late Luphomoid warlord Zorr, enemy of the original Captain Marvel. [Nova (3rd series) #1]
- Thanos Annual (2014) stated that Nebula had said she is Thanos daughter as opposed to granddaughter. This may have been an error or a stealth retcon/ attempt at “synergy,” as Nebula is an adoptive daughter of Thanos in the Marvel cinematic universe.
- In Nebula #2, another take was shown with her having a large family life, with a sister, brother, grandparents etc. However, she was amnesiac at the time she got this flashback, so these memories may have been false and the series was never finished.
Regardless of her true origin, when news reached Thanos that Nebula was claiming kinship to him, he reacted violently. As a servant of Death, he found her claim unforgivable and punished her by placing in her a petrified, zombie-like form. After his acquisition of the Infinity Gauntlet and murder of half the beings in the universe in tribute of Death, Thanos created a bride in his own image, Terraxia, to love him, feeling that Death's own love was unattainable. Thanos kept Nebula, along with his brother Eros, prisoner in his temple to bear witness to all the destruction he had wrought. They were both present for his battles with the remaining heroes and loss of his new bride Terraxia in combat. Nebula's infirmity notwithstanding, she was still savvy enough to use the opportunity during the assault of Thanos’ enemies to take control of the Infinity Gauntlet herself, reversing time 24 hours to undo all the damage Thanos had done to universe. She failed to take into account that, by turning back time, she had reverted herself to the zombified state, albeit briefly. This short interlude proved enough time for Nebula to be incapacitated and she lost the gauntlet and was taken to prison by her alleged great uncle Starfox. Unsurprisingly, Nebula's incarceration did not last long and she was again terrorizing the known universe. To date her claim of ancestry to Thanos' has remained unproven. [Silver Surfer (3rd series) #38, 45, Infinity Gauntlet (1st series) #1-6]
Someone with proven heritage to Thanos is the aptly named Thane. Thanos had impregnated an Inhuman woman while she was traveling the outskirts of known space. There was an implication from the Inhuman king Black Bolt that this pairing may not have been consensual, as he said “dark things in dark places occurred.” Aware of his heritage, Thane lived as a doctor in the Greenland-based Inhuman community of Orolan as a healer. Aware of who Thanos was and what he represented, Thane sought to be the antithesis of his father. This all changed when Thanos journeyed to Earth, searching for Thane and intending to kill him as part of his earlier agreement with Death. In an attempt to hide Thane, the Inhuman king released the Terrigen bomb, spreading it across the planet and activating the powers of all those of Inhuman descent. The advent of Thane's Terrigenesis not only physically mutated him (now wearing the face of his father), it brought destruction to Orollan, wiping out the community with Thane's new death based abilities. Thanos managed to track down Thane, who would have been murdered by his father if not for the intervention of the Avengers and the betrayal of one of his father's chief lieutenants, Ebony Maw. Managing to use the distraction of the Avengers, Thane used his new powers to encase his father in an amber prison of living death. Thane then then fled Earth under the tutelage of Ebony Maw. [New Avengers (3rd series) #11, Infinity #4-5]
Maw manipulated Thane and turned him into a despot, only for him to be deposed and incarcerated by one of his father's other former generals, Corvus Glaive. While imprisoned in solitary confinement, Thane (now quite insane) found himself seduced by Death. Death and Thanos were on one of their infamous “breaks” and she had punished him by inflicting a form of cancer on him that was gradually killing him and removing his power. In this weakened state, Thane proposed to kill Thanos and recruited Starfox and possible niece, Nebula. Terrax was in possession of a Phoenix Egg and Thane tricked Nebula and Starfox into helping him steal it so he could absorb its power. He had told his family that they were rescuing a valuable prisoner with tactical information about Thanos. When Nebula realized Thane's true goal, she killed him. This was a gross miscalculation on her part as the egg needed a sacrifice as a catalyst and Thane's dying body fell allowing him to absorb its power.
Thane proved a poor host for the Phoenix and began on a path of destruction. All the while, Death whispered in his ear as she had done with Thanos all those years before. Seeing no other option Starfox, Nebula and Thanos worked together to defeat Thane, leading him to the area known as the God Quarry. In the Quarry, Thanos was able to remove Death's curse and acquired the additional power needed to fight the Phoenix-empowered Thane before having a trio of witches, who resided in the quarry, strip Thane of the Phoenix. Without his cosmic power, Thanos simply tossed Thane over a ridge in the quarry, seemingly trapping him for eternity. He also marooned Nebula and Starfox on the planet (although they later escaped) claiming he needed no family. [Thanos (2nd series) #4-12]
[Note: Thanos had actually murdered A'Lars in Thanos (2nd series) #2 while searching for a cure for his condition but Starfox appeared to be unaware of this throughout the story. He has since been mentioned as resurrected along with Sui-San in Eternals (5th series).]
Thanos' parental skills for his natural born children are undoubtedly horrific but he did manage to form a dysfunctional fatherly relationship with the alien, Gamora, last of the Zen-Whoberis. Thanos rescued her from an alternate timeline in which her people were wiped out by the Universal Church of Truth. In the child he saw an opportunity: Gamora, as a chronal anomaly, could be a useful assassin against his enemy, Magus. Eventually under Thanos' tutelage, Gamora earned the moniker of the “most dangerous woman in the universe.” Thanos and Gamora's relationship has been combative at the best of times but historically there has been regard for the other and she seems to have been Thanos' healthiest relationship. Thanos' enemy Magus theorized that the reason Thanos' fatherly bond with Gamora was possible was she did not remind him of himself, like his natural born children. [Warlock and the Infinity Watch #9, Avengers Annual (1st series) #7, Thanos (3rd series) #1-6, Infinity Wars Prime #1]
Gamora did rebel against Thanos, however, when she realized he was a despot. In later years, however, despite her antipathy for him, she did follow in his footsteps by recreating the Infinity Gauntlet, even killing him in the process. Unlike Thanos, she did not kill half the living beings in the universe; she merely halved the population by merging each living being with one other being [Infinity Wars #1-6] When her actions were undone, Gamora went on the run. Thanos had prepared for the eventuality of his death and put in place a system for resurrection, having backed up his consciousness in an unwitting host so he could start again. Initially, Gamora was heavily suspected by the interstellar community of being this “host,” given her recent actions. However, it turned out to be the more obvious choice of Starfox, Thanos’ brother. Seeing no choice, Gamora slew her adoptive uncle, preventing Thanos from this mode of rebirth and by proxy restored her own reputation among her peers. [Guardians of the Galaxy (5th series) #1-6]
Notwithstanding Gamora's best efforts, Thanos and Eros, along with both their parents, have been revived in Eternals (5th series)/A.X.E events where it was revealed that both brothers were the first and only examples of sexual reproduction between two Eternals, therefore both brothers are in fact "True" Eternals. The crime of creating Thanos resulted in Mentor and Sui-San being excluded from Eternal society. During a coup, Thanos briefly assumed control of the Eternals and repeatedly killed his parents, though he was thwarted in permanently killing them, as alas, just like he they are all "eternal".
The Thanosi
The duplicates of Thanos (or “Thanosi” as they are also called) are a combination of android, clone and mystical doppelganger. Thanos claimed that duplicates were created with the intention of testing the abilities of his enemies and possible allies. For the most part, they appear to have done Thanos' bidding. However, a group of five (named Armor, Mystic, Omega, Warrior and X) did gain independence. Like their malevolent sire, they were nihilistic in nature and schemed to destroy the universe. All were killed by Thanos and a combination of Earth and cosmic heroes before their plans came to fruition. [Infinity Abyss #1-6, Avengers: Celestial Quest #1-8, She-Hulk (2nd series) #12-13]
The Uranos Line
Uranos resurfaced in 2020s comics becoming a very real threat for the X-Men. His backstory was changed in Eternals: The Heretic #1 that he had been impriso
ned by his brothers following genocidal actions against the Deviants. During the Judgement Day event he was temporarily freed by his grandson Druig and slaughtered many on the Planet Arrako before being imprisoned again. As a way of apology, his services were offered to the X-Man Storm for one hour in the future at a time of her choosing. His family line was expanded to include four other promiment Eternals characters in Virako, Valkin, Ikaris and Druig. Virako is the leader of the Eternals in the outpost, Polaria. His son Ikaris is normally the protagonist in most Eternals storylines. No mother has been listed for Ikaris, possibly he doesn't have one.
Ikaris is famously one of the most “mortal” focused of the Eternals crediting his name as an homage to his son Icarus. Ikaris claimed his son was born to him and a human woman during the Minoan period in ancient Crete. Ikaris said he was happy for this time with his little family however his duties as one of the Eternal champions kept him busy and often away for long periods of times. During a period of excessive separtion, he claimed his son went looking for him using mechanical wings he had made for him during a trip to Olympia. The poor boy flew close to the sun and plummeted to the ground. Ikaris said he took his son's name to honor him. [Eternals (2nd series) #5]
Druig exists as possibly the shadow of his cousin, Ikaris and it could be argued he is the Eternals most consistent antagonist. Debuting in Eternals (1st series) #11, like Ikaris he is the son of a well respected Eternal warrior, Valkin, also no mother is listed for Druig. In many ways he is the Eternals answer to “Maximus the Mad”, a vengeful and unpredictable telepath who has made many attempts to gain control of the Eternal society with the results varying in both success and sustainability. Ikaris and Druig are often opposed though their familial rivalry is only compounded by Ikaris close relationship with his uncle and Druig's father, Valkin. [Eternals (5th series), Thor Annual (1st series) #7]
Given the plethora of the changes that have occured within this “families” history it can be clear nothing is Eternal when it comes to the Eternals.