The grey whale (Eschrichtius robustus) is a baleen whale species currently restricted to the North Pacific. Palaeontological and archaeological evidence has, however, revealed that the species was once also present in the North Atlantic, having migrated from the North Pacific by 50,000 cal BP. These Atlantic Ocean populations were then extirpated in historical times, perhaps around the 12th century AD in the eastern Atlantic and by the 17th/18th century AD in the western Atlantic. In the past decade several individuals from the North Pacific population have been sighted in the Atlantic, suggesting the species might return to European waters in the future. If the species returns, strong conservation actions need to be implemented implemented in order to safeguard its recolonization of European waters. Modern marine management strategies are often reliant on data which lacks the long-term perspective that archaeology can contribute. Informing these modern approaches to protecting the grey whale can be achieved through investigating baseline data in prehistoric and historic periods. It is the aim of this project to apply an interdisciplinary approach, combining archaeological/historical methods, traditional zooarchaeology, ZooMS analysis, stable isotope analysis, and aDNA analysis on a step-by-step basis in order to identify past species selection by whalers, the past space/time distribution of the grey whale in European waters, reconstruct the past migration route(s) and feeding ecology of grey whales in European waters, and reconstruct grey whale demographic history and genetic diversity. This will reveal what factors led to the extirpation of the grey whale from the eastern Atlantic and whether anthropogenic pressure played a role. Besides the archaeological and historical implications, the results will also have implications for conservation actions, potentially allowing for more effective conservations actions if the grey whale recolonizes the North Atlantic.