Two major debates frame Arctic prehistory: the emergence of specialized maritime economies that support sedentism and growing socio-political complexity, and the role of these economies in the transition from Paleo-Inuit to Neo-Inuit traditions. This shift, originating in the Bering Strait, led to Thule Inuit dispersal across the Arctic, impacting Indigenous communities today. However, understanding these themes is still hampered by the challenges of building accurate site-based and regional-scale radiocarbon chronologies, influenced by driftwood use and marine reservoir effects. This paper presents a new high-resolution chronology for the key Ekven mortuary complex, located on the western shores of the Bering Strait, a site that defines the Old Bering Sea (OBS) phase, marking the earliest onset of the Neo-Inuit tradition. It is based on new direct radiocarbon dates of ancestral human remains and Bayesian modelling using OxCal, which considers available stratigraphic information, individual diets, previously dated faunal remains, and appropriate and species-specific ΔR values to account for marine reservoir effects. Our results suggest that the OBS emerged in this region at around 500 CE, which is later than some models predict, and indicate that the mortuary complex was used intensively until c. 1000 CE, after which few individuals were buried. The revised chronology also creates new opportunities to better integrate diverse cultural and palaeoecological proxies from across the Bering Strait, potentially clarifying the precise role of climatic and environmental factors at a key cultural juncture in Arctic prehistory.