This paper discusses three problems concerning the Woodland Grayling,Hipparchia fagiScopoli, 1763, with respect to the identity and application of the junior namePapilio hermioneLinnaeus, 1764. In 1977, the late Otakar Kudrna designated a specimen of the Rock Grayling,Hipparchia alcyone[Denis & Schiffermüller], 1775, to become the lectotype ofPapilio hermione– as a result of whichhermionesupplantedalcyoneas the senior epithet for this species. BecauseP. hermioneis the nominal type species ofHipparchiaFabricius, 1807, Kudrna’s action rendered this a genus based on a misidentified species. Third, while a majority of lepidopterists have ignored Kudrna’s action and continue to apply the nameH. alcyoneto the Rock Grayling, and still regardP. hermioneas a junior subjective synonym ofH. fagi, the formal nomenclature for the Rock Grayling has become unstable because a large minority have nonetheless accepted Kudrna’s lectotype designation and all that follows from it. It is demonstrated here that no syntypes ofPapilio hermione(orPapilio fagi) have survived; consequently, Kudrna’s lectotype designation forP. hermioneis invalid. By designation of a single specimen of the Woodland Grayling as neotype for bothP. fagiandP. hermione, the two names are rendered objectively synonymous, thereby restoring stability to the species name for the Rock Grayling (asHipparchia alcyone), and to the application ofPapilio hermione(=Hipparchia fagi) as nominal type species of the generic nameHipparchia.