Khmer: The Lost Empire of Cambodia (UK title: Khmer: Lost Empire of Cambodia; French: L'Empire des rois khmers, lit. 'The Empire of the Khmer Kings') is a 1997 illustrated monograph on the culture and history of Khmer Kingdoms. Written by Thierry Zéphir, a professor of the École du Louvre, and published by Éditions Gallimard as the 310th volume in their "Découvertes" collection, in collaboration with the Réunion des Musées Nationaux.