Aberforth Dumbledore
Wikipedia
Harry Potter Character Guide
Aberforth Dumbledore is Albus Dumbledore's brother. He is the younger brother by some three years and the less skilled of the two; as such, he is usually left in the background while his brother basks in the glory of his comparative success. His first appearance is in the book Harry Potter and the Goblet of Fire. After his parents' deaths and Albus' return home to look after their unstable sister Ariana, Aberforth quarrels with his brother and his brother's friend, Gellert Grindelwald, over their plans to start a new order, neglecting Ariana. Grindelwald began torturing him, leading to the three dueling. This argument results in Ariana's accidental death at the hands of one of them. At Ariana's funeral, Aberforth publicly confronts Albus and strikes him, breaking his nose. Eventually, Aberforth becomes the owner and barman of the Hog's Head inn. He is known for his strong affinity with goats. His Patronus takes the form of a goat, and he recounts to the trio that as a boy he fed the goats in company with his sister, Ariana. Aberforth was also tried before the Wizengamot, the Wizard High Court, for performing inappropriate charms on a goat. His tavern also, according to Harry's description in Harry Potter and the Order of the Phoenix, has a faint smell of goats.
It is not until Deathly Hallows that Aberforth plays an important role in the series by taking Harry, Ron, and Hermione into his bar before the Death Eaters can capture them. Aberforth later reveals to the trio some facts they did not know about the history of the Dumbledore family. While being held prisoner in Malfoy Manor, Harry briefly glimpses Aberforth's eye in the remaining shard of the two-way mirror he was given by Sirius and calls for Aberforth's help. Aberforth bought its counterpart from Mundungus Fletcher. Using the mirror to watch over the trio, Aberforth sends Dobby to rescue them and the other prisoners from the Manor. He liked Dobby and was upset to hear Bellatrix Lestrange killed him.
Aberforth allows the resistance fighters to use a secure passageway from the Hog's Head to the Room of Requirement through Ariana's portrait, it being the only unguarded entrance into Hogwarts. This passage is used to evacuate underage students from Hogwarts and, according to Neville, it was also used by members of Dumbledore's Army to get food when they were living in the Room of Requirement because that is one thing the Room of Requirement would not do. Aberforth leaves the Order, believing the war against Voldemort is lost. However, he quickly joins the Battle of Hogwarts and is last seen Stunning Augustus Rookwood.
It is not until Deathly Hallows that Aberforth plays an important role in the series by taking Harry, Ron, and Hermione into his bar before the Death Eaters can capture them. Aberforth later reveals to the trio some facts they did not know about the history of the Dumbledore family. While being held prisoner in Malfoy Manor, Harry briefly glimpses Aberforth's eye in the remaining shard of the two-way mirror he was given by Sirius and calls for Aberforth's help. Aberforth bought its counterpart from Mundungus Fletcher. Using the mirror to watch over the trio, Aberforth sends Dobby to rescue them and the other prisoners from the Manor. He liked Dobby and was upset to hear Bellatrix Lestrange killed him.
Aberforth allows the resistance fighters to use a secure passageway from the Hog's Head to the Room of Requirement through Ariana's portrait, it being the only unguarded entrance into Hogwarts. This passage is used to evacuate underage students from Hogwarts and, according to Neville, it was also used by members of Dumbledore's Army to get food when they were living in the Room of Requirement because that is one thing the Room of Requirement would not do. Aberforth leaves the Order, believing the war against Voldemort is lost. However, he quickly joins the Battle of Hogwarts and is last seen Stunning Augustus Rookwood.