When we started the series in Book 1, Neville Longbottom was a lovable loser. He’s kind of clumsy and forgetful, and has a tendency to lose things, especially his toad, Trevor. Through it all, though, he’s a really sweet kid. Still, even in the first book, we learned that there is more to Neville than meets the eye: he is willing to stand up to Harry, Ron, and Hermione when they are about to sneak out of Gryffindor after hours and lose the House more points. Neville is brave. Nonetheless, he seems hopelessly clumsy and ineffective most of the time.
Then comes Book 5, which is a real turning point for Neville. When Seamus Finnegan tells Harry he must be crazy to believe Voldemort back, Neville gets right up in Seamus's face and informs him, "My gran's always said You-Know-Who would come back one day. She says if Dumbledore says he's back, he's back" (11.164). Neville is one of Harry's steadiest supporters. When the time comes to risk going against Professor Umbridge by joining Dumbledore's Army, Neville does it. And with Harry's tutoring, Neville starts improving hugely in his spellcasting. By the time he joins Harry, Ron, Hermione, Ginny, and Luna in the Department of Mysteries at the end of the novel, Neville has become a serious threat to the Death Eaters.
Most importantly, though, we see Neville come to terms with his personal history. In Book 4, Harry learns that Neville's parents, Frank and Alice Longbottom, were both tortured by Death Eater Bellatrix Lestrange for so long that they lost their minds. They are still alive, but they can't even recognize their own son when they see him. It's in Book 5 that the fate of Neville's parents becomes more widely known to his friends.
Ron, Hermione, Ginny, and Harry are all sitting in the Spell Damage wing of St. Mungo's hospital after Christmas (to see why, check out our "Character Analysis" of Mr. Weasley) when Ron looks over and sees Neville accompanied by a stern-looking elderly woman, his grandmother. Ron shouts Neville's name and runs over to greet him. Neville's grandmother is shocked to learn that Neville hasn't told his friends that his parents are currently living in St. Mungo's wing long-term: "They didn't give their health and their sanity so their only son would be ashamed of them, you know!" (23.200). So, the truth about Neville's parents and their torture at the hands of Bellatrix Lestrange comes out by accident.
Despite the unexpected nature of this revelation, Neville does seem ready to open up about his parents' horrible assault. Like Harry, he was essentially orphaned by Voldemort, and he admires Harry's interview with The Quibbler, saying, "It must have been ... tough ... talking about it ... was it? [...] people should know ..." (26.6).
Finally, in the Department of Mysteries, Neville must confront his own personal demon, Bellatrix Lestrange. As Bellatrix mocks him for what she did to his parents, Neville bravely insists that Harry absolutely cannot hand over the glass prophecy ball. Even when Bellatrix casts the Crucio curse on Neville – the same spell that drove his parents insane – he still stands strong. Much like Harry, Neville faces the person who tore apart his family, who ruined his life, and stands strong.
In fact, this doubling between Neville and Harry is no accident. Neville, like Harry, was born at the end of July. Neville's parents, like Harry's parents, defied Voldemort three times. So, Neville and Harry were both candidates to fulfill the prophecy that Voldemort has been trying so desperately to find at the Department of Mysteries. But Voldemort himself chose which of them would be the prophesied boy by coming to attack Harry fourteen years ago. Voldemort chose Harry by giving Harry the curse scar that connects the two throughout the series. Yet, even if Neville isn't the chosen one now, he could have been. Book 5 underlines that there is more to Neville Longbottom than meets the eye.