In Paul of Dune, Ipyr is the homeworld of Earl Memnon Thorvald, a nobleman who leads the resistance against the rule of Paul "Muad'Dib" Atreides after the events of Dune. When Paul discovers Thorvald's intent to devastate the Atreides planet of Caladan, he forces the Spacing Guild to eject Thorvald and his followers into deep space and leave them to die. Paul's forces then "sterilize" Ipyr, using "weapons, explosives, highly toxic chemical bombs, defoliants, and wide-dispersal incendiaries" to destroy every living thing and render the planet uninhabitable.
Read more about this topic: List Of Dune Planets