This article contains information from recently released episode(s) and/or manga(s). It may contain SPOILERS.
All humans on Earth are the descendants of Noah and his family, who survived the Great Flood and populated the Earth once more. Every so often, and when there is a vacancy within the Family, a gene within a regular human, called the "Noah gene", awakens, turning that human into a Noah and causing them to fall under the influence of his hatred and memories stored within their blood.
At their greatest, the Noah Family will have fourteen members, including the Earl of Millennium who leads them. When one of the members dies, an indeterminate amount of time later the same Noah will awaken in a new human, though under a new human name and a new human mindset. The process is progressive and extremely painful causing Wisely to push a piercing cry and Skin Bolic to bite his fingers every night.
When the Noah finally awakens, the pain stops and the Noah sees a 7000 years old truth and is revealed "the world as he really is".  Depending on the memory the human seems to be able to refrain the memory and prevent it from taking over while keeping their original personality.  Depending on the the use of their power the Noah may no longer be able to refrain the memory and eventually loose his self.
The memory that reincarnates seems to remember the events of his past reincarnations even when the reincarnation doesn't.
Each member of the Noah Family is known as an 'Apostle', and each Apostle has their own Noah name, though a few choose to continue to go by their human name. Road Kamelot has declared them to be the true Apostles of God .Several members have claimed to hate regular humans and to consider themselves superior.
Physical and biological caracteristics
The Noah Memory inside a human appears in the form of a blank. A humanoid figure without hair, eyes or nose whose only feature is a grinning mouth. It was shown to reflect on mirrors of the physical world in some circumstances. In some situations it can even manifest physically on the host as shown on Skin Bolic's forhead, Tyki Mikk's tentacles or Feedler's belly. It feels an intense, visceral and in-suppressible hatred towards Innocence.
Members of the Noah Family, when they are in their Noah forms, are distinguished by their greyish darkened skin, amber eyes, bluish black hair (with the exception of Jasdevi, Wisely, and Allen), black nails and the line of seven or nine black, cross-like markings that go across their foreheads, called stigmata. A few Noah have an additional Iris. Some have shown to even be able to darken their sclera. 
They are able to transform only parts of their body in their Noah form as examplified by Road Kamelot who made appear stigmata on her human skin or change only her eyes . Tyki Mikk has showed a intermediary form with a brown skin between the traditionnal greyish and his human skin color.
When submerged by his memory, Tyki Mikk has black blood.
Tyki Mikk has also developped a marking identical to a stigma on his throat after the failed exorcism attempt of Allen Walker.
When a Noah reawakens his body is reborn down to his cells, making them superhumans. They then age slowlier and keep young bodies for a long time. 
Seven thousand years before the main story started, the Noah fought the first users of Innocence in a battle so great it destroyed the world, an event known in the Old Testament as "The Great Flood", though it is documented in the Cube as "The Three Days of Darkness". After the first incarnation of the Earl died fighting against the wielder of the Heart of the Innocence, the remaining twelve Apostles repopulated the Earth, making Noah's blood the ancestor strain of all humans of the current generation.
Some time afterwards, the Millenium Earl was reborn, as well as the remaining Noah family, due to their genes being dormant inside all the population of the Earth as their descendants. According to Wisely and the Earl himself, various people awakened as Noah in each era to protect the Earl and fight alongside him against the Innocence. At some point the Earl of the Millenium disappeared from this world, something that happened only once during 7000 years.
Thirty-five years before the main story, the fourteenth Noah, Nea Walker, betrayed the Family, killing all except Road and the Earl before being killed himself. Because of the memory damage caused by Nea, the next generation of Noah was reincarnating slowly enough for the last awakened Noah to appear only with pass of these thirty-five years, although the current Noah Family is still incomplete (due to the recent Wrathra reincarnation, Skinn Bolic, dying from the hands of Kanda Yu). The Fourteenth managed to implant his memories into Allen Walker before his death, thus getting a chance of being reincarnated as well. In the course of events, he slowly awakens inside Allen and manages to announce his rebirth to the Earl. Though he desires to become the new Earl of Millennium, the current Earl still misses him and wants to have him by his side again, believing he can convince Nea to join them. On the other hand, not all the
Noah are fond of accepting Nea into the Family, Sheril being the main example, seen when he decided to question the Bookman (who was close to the previous Noah generation) about Nea's weakness and declared they'd kill the Fourteenth without any doubt, despite their pledge to protect Nea from the Heart with their lives.
|Noah Family Members|
|Apostle||Noah Name||Human Name||Representation||Status|
|1||Adam||The Earl of Millennium||Active|
|8||Wrathra||Skinn Bolic||Wrath||Deceased †|
|10 & 11||Bondom||
Jasdevi (Jasdero and Devit)
|14||Nea||Nea D. Campbell/Allen Walker||Defected/Reincarnated|
Inherent Noah Abilities
Natural command of all Akuma: All Noah have the ability to command Akuma to do whatever they want, both verbally and telepathically. The extent of this influence is so complete that Noah can command Akuma to self-destruct, even if it is against the Akuma's will.
Akuma Blood Oil Immunity: Though they are human, Noah are immune to the poisonous effects of Akuma blood oil, though it is noted by Jasdevi that it tastes terrible. Road however likes the taste of Akuma Blood Oil.
Physical Prowess: It was shown that even without training, Noah are naturally able to physically endure things that would fatally injure regular humans. This is only enhanced for the Noah fighters who can easily overpower trained humans and even take on several exorcists at once.
Noah's "Memory": The driving force behind the will that all Noah feel, it creates their thirst for blood and their hatred of Innocence and those who wield them, and, when a Noah is in a life threatening situation, it awakens their full potential, increasing their power and stamina dramatically.
Familial Empathy: Noah are able to sense when a member of their 'family' dies, a situation that seems to sadden the Noah within them, as shown when Skinn Bolic died and Tyki was unable to explain why he was crying. Road, who was also crying at the time, explained that Noah was crying.
Dark Matter abilities: All Noah members have their special abilities based off Dark Matter, which grants them each a unique and powerful ability, making them deadly fighters. This also makes them vulnerable to Innocence, but at the same time, allows them to destroy Innocence by merely touching one. They can also use dark matter in a more mundane way to shoot dark matter blasts .
Innocence : Like every Dark Matter empowered being, Noah are vulnerable to innocence. Their otherwise universal abilities don't seem to apply to Innocence which "doesn't belong to this world". For instance, Tyki Mikk can't phase through innocence and Road cannot suck Apocryphos in her dimension.----
The Earl of Millennium : It is revealed by Road that if the earl of millennium disappears , all the noah will be destroyed by the heart of Innocence. In that way the earl acts in a similar way for Noah as the heart does for innocences.----
- It is unclear how Nea Walker, the fourteenth Noah, fits into the Noah reincarnation cycle, as it is explained by Wisely that there were only thirteen original Apostles, the Earl of Millennium included. Though if both Bondomus (Jasdevi) are combined they make just one person, thus making Nea thirteenth one.. It is later revealed that both Nea and The Millennium Earl were originally the same entity that reincarnated into two forms.
- "Stigmata", by definition, are marks of disgrace associated with a particular circumstance, quality, or person. In the Roman Catholic faith, the word is given to bodily marks, sores or sensations of pain in locations that correspond to the crucifixion wounds of Jesus Christ.
- Wisely is the only Noah who remembers his previous incarnations.
- The Number of Noah (considering Bondom as one) is the same as Jesus in his apostles. This makes the Earl betrayed by Nea highly reminiscent of Jesus betrayed by Judas.
- The exact shade of the dark noah skin stone is unknown. It has varied during the different depiction of the anime and even those of the manga author, being sometimes grey (first anime and early artwork), sometimes brown (hallow and more recent artwork) and even having sometimes some shades of green (volume 19).
|The Noah Family|
|Noah:||The Earl of Millennium • Road Kamelot • Tyki Mikk • Skinn Bolic • Jasdevi • Lulu Bell • Nea Walker • Sheril Kamelot • Wisely • Tryde • Feedler • Mercym • Mightra • Allen Walker|
|Akuma:||Mana Walker • Claire • Leo • Pierrot • Eliade • Eshi • Thread • Chomesuke • Lesley • Alma Karma • Mimi • Doug • Ice • Pang • Kazekiri • Sara • Doug • Sophia • Wizard Akuma • Rabbit Akuma • Level 3 (Paris) • Level 4 (Headquarters) • Level 4 (Paris)|
|Other:||Dark Matter • Noah's Ark • Cell Roron • Lero • Teez • Akuma Egg • Skull • Brokers • Golem|