well, he did vanquish the dark lord when he was a baby. this fact remains to be the same. however, when the young hero was ten years old, using an uncontrolled act of magic, managed to find his way on the roof of his school. while he was attempting to climb down, he fell. he fell to his death. poor harry potter never knew of his powers or a school he could call home.
one year later, voldemort procured the philosopher's stone and returned to full power. his old followers flocked back to him. without a boy named harry potter on his mind, voldemort was free to take over the wizarding world with brute force.
it's now 1996. hogwarts is only attended by purebloods and halfbloods. muggleborns have replaced the house elves. they live in lowest parts of the castle serving students and being tourtured. it seems like there's no hope for the muggleborns.
or is there? neville longbottom and ron weasley want to help the muggleborns. they've set up a secret school in the room of requirement. they aim to teach the muggleborn's magic and stage their own uprising. they're called harry's army.
this was taken from HOPELESSLY HOPEFUL at Caution 2.0