Sandy coastal barriers are abundant along most continents, and they are often
intensively engineered to prevent erosion. Therefore, it is important to develop
projections of the evolution of this coastal type in periods with changing climate and sea-level. We have used a multidisciplinary approach combining facies analysis of ground penetrating radar profiles and sediment cores, and optically stimulated luminescence dating to reconstruct the history of the Rømø barrier island (Denmark) over the past 8000 years. This approach allows us to develop a high resolution 2D reconstruction of the formation of the barrier island system, and to interpret it in relation to sea-level changes. We found that the various subsystems constituting the barrier system responded differently to Holocene sea-level variations. Beach and shoreface deposition took place during periods of slowly rising sea-level, still stand, and falling sea-level, whereas wash-over sedimentation was promoted during periods of rapid sea-level rise when shoreface, beach and coastal dune deposits were reworked. In contrast, lagoonal sedimentation has been relatively continuous and kept pace with the
long-term Holocene sea-level rise. Our findings have implications for the development of new conceptual models for barrier island formation.