Who is the Half-Blood Prince?

The story behind the answer

Severus Snape is the Half-Blood Prince. In Harry Potter and the Half-Blood Prince, Harry finds an old Potions textbook filled with ingenious annotations and original spells, signed “This book is the property of the Half-Blood Prince.” The title comes from Snape’s mixed parentage—Muggle father Tobias Snape (half-blood) and witch mother Eileen Prince (“Prince”). He later reveals the alias as his own.

Context: The annotated book showcases Snape’s brilliance in potion-making and spell invention (like Levicorpus and Sectumsempra), deepening his complex role in the story. Memory tip: “Half-Blood” = mixed heritage; “Prince” = his mother’s maiden name. Not Dumbledore, Lupin, or Tom Riddle—though Riddle is also half-blood, his chosen name is Lord Voldemort, not the “Prince.”