The Boy Who Lived
From UnknowableWiki
The Boy Who Lived is a nickname attributed to Harry Potter by many people of the wizarding world after Harry, as a one-year-old baby, survived Voldemort's Killing Curse, which rebounded upon the Dark Lord and caused him to disappear (PS1). The title serves as a kind of symbol, creating hope in those who have to face Voldemort in the Second War (DH22).
Voldemort uses the title sarcastically just before using the Killing Curse on Harry, when the latter goes to the Forbidden Forest intending to die; the Dark Lord states, "Harry Potter...The Boy Who Lived," and then casts the curse (DH34). Ironically enough, Harry survives once more (DH36).
This article has to be revised, because it needs more references to the title.

