"The four of you stand accused of capturing an Auror - Frank Longbottom - and subjecting him to the Cruciatus Curse, believing him to have knowledge of the present whereabouts of your exiled master, He-Who-Must-Not-Be-Named. You are further accused of using the Cruciatus Curse on Frank Longbottom's wife, when he would not give you information."
-- Barty Crouch Sr. (GF30)
A group of Death Eaters — Bellatrix Lestrange, her husband Rodolphus, and Rodolphus’s brother Rabastan, along with Barty Crouch Jr. (although this is never explicitly confirmed) — torture Frank Longbottom with the Cruciatus Curse in the belief that he knows the whereabouts of Voldemort after the defeat in Godric’s Hollow. When Frank tells them nothing, they proceed to use the Curse on his wife Alice. The attack leaves both Frank and Alice with permanent mental spell damage.
c. 1984 to 1986 (for reasoning, see "When were Frank and Alice Longbottom attacked?")