The Harry Potter franchise starts with Voldemort killing Harry's parents, James and Lily Potter, but it isn't until Harry Potter and the Order of the Phoenix that the audience finds out the reason behind this. The titular wizard of the Harry Potter series became renowned, in part, due to his signature lightning bolt scar, both within the Wizarding World and in pop culture. He earned that telltale scar the night he survived an assassination attempt by one of the evilest wizards who has ever lived.
Source：https://www.cbr.com/why-voldemort-killed-harry-potter-parents/
