A multi-proxy approach to infer the environmental evolution and coastal dynamics was conducted on four sediment cores with the aim to decipher forcing factors shaping the coastline of Acholla (Tunisia) over the last 2000 years. The data recorded from palaeontological and sedimentological studies combined with 14C dating suggest a progression of four successive phases: (1) the first Holocene marine transgression (183 A.D.), overlying Upper Pleistocene marine sandstones, resulted in a brackish shallow-water coastal environment characterized by a mixture of lagoonal/estuarine, marine/brackish and marine/lagoonal ostracod assemblages with high species richness, (2) a high-energy event marked by the deposition of coarse bioclastic sands, rich in molluscs, charcoal particles and Tyrrhenian lithoclasts (towards 417 A.D.), (3) progradation of the coast (between 417 and 1577 A.D.), where longshore current drifts and a period of flooding/detrital input resulted in the build-up of a sandspit and the deposition of coastal sand bars, as indicated by increasing abundances of predominantly lagoonal/estuarine ostracods and molluscs. The natural sedimentation pattern was impacted by the construction of a Roman pier that accelerated the formation of the sandspit from 1577 A.D. onward (4), ultimately resulting in the complete closure of the lagoon as recorded by the expansion of saltmarshes containing a monospecific ostracod fauna (Cyprideis torosa).Read less <