During the Pleistocene ice ages central European landscapes were dominated by tundra and steppe vegetation. Deciduous trees were forced into refugia mainly in southern, but also in central and eastern Europe. In contrast to tree species, little is known about the phylogeography (i.e. the historic dynamics of species´ ranges explored with molecular genetic approaches) of forest understory herbs. We will reconstruct the Last Glacial Maximum refugia and postglacial migration routes of six herbs, which are strongly associated with beech (Fagus sylvatica), the most abundant deciduous tree in central Europe. By comparing individual phylogeographies of these beech forest understorey species (BFUS) to each other and to those of deciduous tree species we will clarify whether they responded to the climatic changes since the Last Glacial Maximum in an independent or concerted manner. Based on this knowledge we will further aim at explaining why most BFUS occur only in a fraction of the distribution range of beech. To this end we will quantify the relative role of migration abilities and ecological requirements of species as limiting factor for the postglacial spread of BFUS. Our study will, thus, strongly increase the knowledge of the genesis of the biodiversity in forests in general and of the biogeography of temperate forest understory herbs in particular.