Ventru
Was born as a daughter of a tribal warlord during the time of the First City, their tribe was conquered by the First City and added to the armies Caine was using because "Oh God, Infinite Werecreatures, Fairies, weird demon cults, and more. I need more people to run this and keep humanity from dying off" And was taken as a Ward "Totally not a hostage" but treated okay, as many were. In part due to the fact that the 2nd Gen were infertile like other vampires, and Caine saw wards as a way to give them a semblance of it and allowed the 2nd Gen to eventually ghoul such Wards.
That didn't always work out very well, as Ventru and Mekhet later found Tzimisce, another Ward of Enoch, now a vampire, raving mad, and splattered all over a dungeon as a mass of gibbering meat driven insane by having Enoch's Beast and Malice inside of him.
Ventru brought this information to Caine, who told Enoch to Embrace Ventru, then staked Enoch, removed the insane Tzimisce from his cell, and put Enoch there as punishment. Caine set Ventru as the new Hand of Caine to replace Enoch and gave the Antedeluvian the job of handling matters in the city and mediating between vampires, their numbers slowly growing with more 3rd Generation vampires as Caine pushed in the wars with other supernatural beings.
After the Deluge, Caine had Enoch freed from his cage and join the Antedeluvians in the Second City before going off into the wastes in despair over what happened, reaffirming Ventru's role as the one in charge.
Everyone almost immediately took issue with this and started hoarding the weapons from before the Deluge or making new weapons while embracing childer. Ventru collected her own horde of much better stuff left to her by Caine, but Obfuscate 10 is the kind of stuff which gets past security measures and a few of the Antediluvians did so. She left the city to find Caine and get help, but was staked by the recently Wyrmed Set leading to the 3rd Gen Uprising and fall/diablerie/torpor of the 2nd gen.
The resultant constant agony from a Wyrm corrupted stake to the heart resulted in Mekhet and Tzimisce performing a Koldunic ritual to move Ventru over to a new body (There is a Koldunism Ritual for that), which allowed Ventru to fake her death and move around without the other Antes thinking that she was alive before eventually getting staked by Lucian (Apostate) and left in Carcassonne.
Lasombra
Sired by Irad the Strong due to having been one of the early sea explorers, the Antediluvian was ordered to organize the First City's naval campaigns (Wars with weresharks and Lilith's monstrosities). Studying these enemies led to Lasombra becoming heavily involved in the occult studies of the First City and the development of Obtenebration.
Lasombra LOVED Obtenebration and became far too interested in the latter of his enemies, attempting to replicate their abilities and considering it better than vampirism. When the Deluge came, he tried to swim into the darkness beyond, but failed and was incredibly angry about his inability to get over to the other side that time. He was convinced Irad to lead the Rebellion but failed to Diablerize his sire during that, leading to him fucking off to an island and focusing on trying to explore the abyss, attempting to find the deepest section of it. His siring of others was mainly focused upon obtaining more researchers to better understand his passion project.
By the time of his "Diablerie" he came to believe that nothing more could be learned on Earth, and allowed his body to be destroyed, having turned all of his blood into shadows that had already slunk off and delved into the Abyss.
Unfortunately for him, he found the center, and was promptly mindbroken by The Grand Maw and turned into its servant/extension, which he is deeply unhappy about and is trying to find a way to take control
This would be very bad for everyone.
Gangrel (Ennoia)
A Child of Lilith born during Lilith's travels alongside several others. Arikel (Toreador), Malakai, Mekhet, Churka (Ravnos), and Malkav. Each was twinned with one or another (Churka in her case) and with the exception of Mekhet and Arikel, became the lovers of their twin while being told that Lilith had born a set of twins by Lucifer, Adam, and Caine (While never telling which set who each ones specific father was). At this time, they were mages, but were raised outside of human society and had no understanding of it. The Curse of Lilith ensured that they did not care for their mother, and the six eventually left Lilith's side, heading to the First City when they heard of it due to learning of Caine's existence.
Their "Father" promptly took them in to make sure that Lilith didn't retain six horrifying super weapons. Ennoia was taken in by Enoch and gained her name by him. He experimented on what Magic did for a long time, attempting and failing to recreate it, eventually frenzying and embracing Ennoia, prompting his attempt to remove his Beast by placing it within Tzimisce. Ennoia had melded with the Earth immediately after her Embrace, and eventually resurfaced once Enoch was in Torpor, learning that her other siblings had been embraced as well.
During this time, she began to work with Absimiliard to hunt various creatures, but became disgusted by his arrogance upon learning that he was attempting to court both her and Arikel while spreading tales of conquest.
What proceeded was the Children of Lilith binding Absimiliiard and beating him nearly to death while placing curses upon him.
Ennoia was then placed on the outskirts of Caine's empire, taking Ikopabe and Lhiannan (Two other Antediluvians) with her as subordinates, and working alongside Churka. During this time, they warred with Early Kuei-Jin, during which Saulot traveled to the enemy lands and later came back. Churka was greatly interested in what Saulot learned, causing a rift between the siblings and eventually coming to blows as Churka betrayed Caine's empire immediately before the Deluge.
The pair did not spend much time in the second city, and were not involved in the uprising due to not being present.
Churka (Ravnos)
Most of his backstory is up there, though he was sired by Irad to be used as a spy.
Troile (Brujah)
A woman embraced by Ilyes in the First City, and thus one of the first members of the Fourth Generation. The slow descent into madness and suspicion that most of the others were entering led to a joint project with Arikel to make artwork that would reawaken humanity amongst them, and had been pretending to be a human assistant of Arikel at the time.
When Ilyes came to Troile and discussed that he had made a mistake, she diablerized him, which Caine revealed he knew, and noted that Ilyes had broken the rules first while not instructing her, and he considered Ilyes's death a proper punishment while warning her that the paranoia she felt should be a sign to not create Childer, noting that the artwork she had made evened the balance for now
During the time of the Second City, she joined her grandsire Irad in an attempt to slay the other members of the 2nd gen and would later leave to found Carthage, listening to a longtime lover of hers, Moloch, when he reappeared. She eventually learned that he was a Baali, but believed that The Children must be kept asleep and perpetuated depravities to keep them away. Canon happens otherwise.
Cappadocius (Cappadocian)
Canon overall, sired by Irad. Wants to eat God.
Saulot (Salubri)
Sired by Enoch and kept in a temple before his rampant siring was revealed. He went over to the Kuei-Jin to learn more of mysticism and morality, attempting to transcend his state. During his travel back, he found the city which the Baali Founders had lived in, slaughtered them, and embraced Three due to considering this a step on his path to Enlightenment.
He spent great amounts of time with Set and Malkav, the former two helping Malkav enter extreme situations to incite his visions, and told them of Kuei-Jin believes, attempting to find the method for the other two to become enlightened, and encouraging Set to take power from the Lupine's enemy and using his beast to subjugate it (This did not work).
Canon otherwise, is currently in Tremere's body underneath Gehenna, fighting for control with Tzimisce. The two dislike each other over their very different treatment by their sire, and Saulot wishes to
Absimiliard (Nosferatu)
Mostly described above, sired by Zillah. His story is mostly the canon one with being obsessed with Arikel and trying to kill her. He had a brother, Lucian, who was embraced as well.
Set
Sired by Zillah he would eventually enter a relationship with Arikel while studying visions with Malkav, and sorcery with Mekhet and Tzimisce. He would be incited by Saulot to gain more power, eating a powerful Bane spirit and growing corrupted by it. By the time of the Second City, he was banished by Malkav for his increasing evil. Irad had sired Osiris by this time and the younger Third Gen was ruling another city which Set visited and eventually stayed within. Mekhet traveled to the area to continue their studies, Set eventually ghouling his mortal wife Nepenthys, why learned alongside. He prepared a ritual which would allow the two to conceive, but Osiris obfuscated himself to take Set's appearance, leading to the birth of Anubis and Set becoming murderous.
This started their Feud, with the pair constantly undermining each other and trying to end the other's life. Mekhet would see Set's insanity and move to Osiris's side until later betraying him once more to Set when Osiris was a mummy/ghost, due to learning Osiris's belief that all Kindred should die.
After this, Mekhet offered the idea of Set reincarnating in the future, ascending to a state which would not have the weaknesses of a vampire, which Set agreed to. In truth, this was an attempt by Mekhet to remove the influence of the Bane spirit which he had devoured.
Assam (Assamite)
An assassin Ghoul of Zillah granted the embrace after the successful killing of the King and Queen of Enoch, Assam was tasked to act as a judge and lawmaker for the First City while Ventru acted as its executive. The two worked alongside each other, and would have a relationship of respect in the First City. When the Baali were revealed to the Antediluvians, he began to mass Embrace childer, placing them in warrior positions under himself, scholars to attend to Ventru, or magi to study under the School of Magic run by Mekhet, Set, Tzimisce, and Lhiannan.
After the Fall of the First City, his relationship with Ventru soured, blaming her leadership for the Deluge. He trained members of his clan to administrate in the Second City, but left to wander as Caine did, but was called back by Saulot upon the beginning of the Second Baali War. As things continued, he came to believe that the constantly bickering Second City was a lost cause, took his most loyal Childer, and left for the Eagle's Nest, abandoning the city to whatever would com next.
Malkav
Mostly discussed above. A son of Lilith given the embrace by Zillah, he was close friends with Set and Saulot, philosophizing them and having them aide in his search for stimuli that would cause his visions to arise. During the Deluge, he fell into the ocean, and was drawn to his mother, who cursed him to drink the blood of the second generation while imprisoning Malakai in the shadowlands. The loss of his lover and a new overwhelming desire drove him deeper into insanity, which was further aggravated by the uprising led by Irad, which resulted in him attempting to diablerize Enoch, losing any grip on reality that he had.
His body was ripped apart by his own prompting to his childer, but the consumption of his blood by his childer allowed him to spread himself throughout all who have either drunk Malkavian blood or been embraced by them. One of his favored childer is beneath Jerusalem, and acts as a hub for his network.
Arikel
Another child of Lilith given to Zillah, Arikel's unlife was soon embroiled with Troile's as the recently embraced 4th Generation Vampire smashed into her studio soon after her own creation, fleeing Ilyes in a panic upon learning that her embrace was not sanctioned. Arikel came upon the idea of a joint project that would move Caine's heart, hoping to obtain leniency for Troile, and succeeding in this. She came to take a lover during the Baali wars, and attempted to kill him upon learning that he was Nergal, and had been corrupting Tzimisce and Troile, feeding into their paranoia and fears while inciting them to go deeper into their vices. This angered her fellows, as they refused to believe that Nergal was one of their enemies, and believed that she was undermining them.
When the Second City Fell, she fled, believing that the two would fall upon her next, and settled in Greece, focusing upon her arts and attempting to recreate the beauty that moved Caine, hoping that such items would bring the other Antediluvians back to the state they had been in before the Deluge.
Tzimisce
While the others believe that Tzimisce is a child of Enoch, he merely has his beast, instead having been embraced by Irad as the two members of the second generation had agreed upon the experiment. The insanity that resulted from ages as Enoch's test subject resulted in this information being lost to Tzimisce, and the mess which is his reformed mind focused on obtaining a form which could not be harmed. He would study magic to transcend his state, joining Mekhet, Set, and Lhiannan in this study, forming early Blood Sorcery, which was then split between Koldunic Sorcery, and Dur-An-Ki.
It would leave the First City and discover Kupala in what would one day become Transylvania, merging with the soil immediately before the Deluge. Using Tzimisce's absence, Saulot claimed that Tzimisce had created the Baali and attempted to kill it, failing, but managing to send the creature into Torpor long enough to miss the uprising in the Second City
