At the end of the last film, Grindelwald told Credence he was really Aurelius Dumbledore – the previously unheard of sibling of Albus. However, that wasn't entirely true. While Credence is a Dumbledore, he isn't the brother of Albus, Aberforth and Ariana. In fact, he's Aberforth's secret son!
Aberforth's son is Aurelius Dumbledore, born after he fell in love with a girl in Godric's Hollow. However, the girl was sent away, either before or after Aurelius's birth. His son was adopted by Mary Lou Barebone and renamed Credence Barebone. Despite the rumors, Aberforth never confided in Albus about his son.
Again, though, it would be hard for Dumbledore to have a younger sibling, or even a younger half-sibling, with Percival locked away. So, if you're wondering how many brothers Albus has, there's only one. If Percival is the father of Aurelius, we'd bet Kendra is not the mother, making him a half-brother.
The Entire Life of Aberforth Dumbledore (1884 - 2022) - Harry Potter Explained
Why is Snape the half-blood prince?
Family. Snape's family background is mostly shown in flashbacks during the course of the last three novels. Snape was born to Eileen Prince, a witch, and Tobias Snape, a Muggle, making him a half-blood (hence the name, "Half-Blood Prince").
By this point, Credence was slowly dying as his Obscurial nature poisoned him, the real reason that his phoenix had come to him, something that Dumbledore had recognised after having seen something similar with his sister Ariana, who was also an Obscurial.
Aurelius was an illegitimate child of Aberforth's. His mother is killed, and as a result Aberforth is unable to care for his son. Credence is taken to America and put up for adoption, a fact known to no one but Leta Lestrange (Zoe Kravitz).
Fantastic Beasts 3 reveals that Credence is Aberforth Dumbledore's illegitimate son. Since Grindelwald was telling Credence the truth about his name being Aurelius Dumbledore, it seemed logical that he's one of Albus Dumbledore's siblings.
Fantastic Beasts: The Secrets of Dumbledore confirmed that Credence Barebone/Aurelius Dumbledore (Ezra Miller) is the new Snape (Alan Rickman) through a very familiar line delivered by Aberforth Dumbledore (Richard Coyle). Fantastic Beasts 3 finally shed light on the Credence being Aurelius Dumbledore plot twist.
Fantastic Beasts: The Secrets of Dumbledore finally revealed that Credence (Ezra Miller) is Aberforth Dumbledore's (Richard Coyle) long-lost son, but his mother could very well be a Gaunt, making Credence related to Voldemort (Ralph Fiennes).
Dumbledore never married, but had romantic feelings towards his childhood-friend-turned-enemy - Gellert Grindelwald. The two were inseparable for a bit of time, but sadly Grindelwald turned to the dark side, and Dumbledore had no choice but to take the one he loved down. He never pursued another after that.
Under the influence of her father, Dolores grew up despising her mother and brother for their lack of magical abilities. She was sorted into Slytherin House at Hogwarts School of Witchcraft and Wizardry and hated her time at the school due to never being given any positions of power.
Dumbledore tells Newt Scamander (Eddie Redmayne) that in 1899, during the same summer that Albus fell in love with Grindelwald, Aberforth also fell in love with a woman from Godric's Hollow. They had a baby boy together, but the woman was sent away before she gave birth, and Aberforth never got to be a father.
Aberforth never forgave his brother until years later, after Albus's unfortuante death at the hands of Severus Snape (Who was actually working on Albus's orders), when Harry informed Aberforth of his brother's regret.
Mary Lou Barebone (played by Samantha Morton) is a fanatical No-Maj campaigner against wizardry and the abusive, adoptive mother of Credence, Chastity, and Modesty.
Quentin Kowalski may be a descendant of Jacob and Queenie Goldstein, though this would breach Rappaport's Law. Queenie and Jacob would need to have left the United States of America to marry as to protect Queenie from prosecution.
Nagini (d. 2 May 1998) was a Maledictus cursed to transform into a snake. Originating possibly in Indonesia, by 1927 she was a performer at the Circus Arcanus where she met Credence Barebone (Aurelius Dumbledore) and had a romantic relationship with him.
Leta had become the fiancée of Newt's older brother Theseus by 1927. In that same year, she sacrificed herself for them during a rally held in Paris by Gellert Grindelwald by distracting him by destroying his skull-hookah with a powerful spell. Grindelwald's flames then engulfed Leta, incinerating her.
Although he wasn't turned into a werewolf, he did develop some wolfish tendencies such as a liking for very rare steaks. He married Fleur on 1 August 1997, although their wedding was disrupted by the arrival of Death Eaters following the fall of the Ministry of Magic.
By Harry Potter and the Deathly Hallows, it's a stretch to call Draco a villain anymore. We just watched — or read — him struggle to reconcile his choices and morals in The Half-Blood Prince. He can no longer justify his actions, and is far more aware of the evil he was born and raised into.
