Frank Longbottom was an Auror and Neville Longbottom's father. He was tortured with the Cruciatus Curse along with his wife, Alice Longbottom. As a result they now reside in St. Mungo's Hospital for Magical Maladies and Injuries in Ward 49. He is unable to remember any of his family members after being struck with the Cruciatus Curse by Bellatrix Lestrange. Because Mr. Longbottom was an auror (not to mention his membership in the Order of the Phoenix) it was assumed that he had valuable information. He either lacked this sought-after information or refused to share it and was thusly tortured until he could no longer speak coherently.