Magical Genealogy is the study and documentation of family lineages within the wizarding world, with a primary focus on ancestry and blood status. This field is of paramount importance in wizarding society, as a witch or wizard's parentage—specifically whether they are of pure-blood, half-blood, or Muggle-born descent—often dictates their social standing, opportunities, and the prejudice they may face. The concept of magical ancestry is a central theme in the *Harry Potter* series, underpinning the core conflict between the forces of Lord Voldemort, who espouse pure-blood supremacy, and those who believe that magical ability is not determined by lineage.
Magical genealogy is not merely an academic pursuit; it is the foundation of the wizarding world's social and political structure. The prejudice rooted in blood status is the primary motivation for Lord Voldemort and his Death Eaters, whose goal is to eradicate Muggle-borns and establish pure-blood dominance. This ideology infiltrated the Ministry of Magic during the Second Wizarding War, leading to the establishment of the Muggle-Born Registration Commission, which persecuted witches and wizards of non-magical descent. Throughout the series, the narrative challenges the validity of blood purity. The most powerful dark wizard, Lord Voldemort, is a half-blood. The most brilliant witch of her age, Hermione Granger, is Muggle-born. Ultimately, the story demonstrates that a person's choices, courage, and character are far more important than their ancestry.