After a long period of substantial economic growth and population increase in the Early Bronze Age, the reason(s) for the relatively rapid disappearance of Únĕtice populations in Central Europe and the subsequent lack of population in much of their former territory for around 200 years remains a mystery. Various theories have been proposed for these developments, such as changed long distance trade routes or the depletion of materials for bronze-making. However, these fail to explain why large areas formerly occupied by the Únĕtice remained unoccupied (or virtually so) for so long after their abandonment by the Únĕtice. We argue on the basis of demographic and other scientific evidence that the collapse of the Únĕtice was in all probability primarily the result of unsustainable ecological development. Human-induced changes to ecosystems eventually reduced agropastoral productivity, substantially reduced the standard of living of the Únĕtice and resulted in the abandonment of many of their settlements. The extent and nature of ecological damage was such that it took much time for natural ecosystems to recover sufficiently before the affected former Únĕtice areas were economically suitable for resettlement. The possibility that resource shortages for bronze-making and changed trade routes contributed to the unsustainable development of Únĕtice settlements is also considered.