Most present day estuaries formed within incised fluvial valleys, created during the last glacial, that drowned during post-glacial sea-level rise. The sedimentary archive of the associated river-mouth areas contains important information on estuarine evolution under different rates of sea-level rise. This thesis presents a study on the development of the mouth of the Rhine-Meuse system in the Rotterdam area, western Netherlands, between 12000-6000 BP. During the study tens of thousands of core descriptions and cone penetration test results, as well as seismic data, pollen and diatom analyses, tens of OSL-dates and hundreds of radiocarbon dates were used. The objectives were to explain: 1) the early-mid Holocene sedimentary succession of the Rhine-Meuse river-mouth area; 2) the development of the river-mouth area in the early-mid Holocene in response to rapid sea-level rise (SLR) and 3) the interaction of the fluvial and coastal systems during the early-mid Holocene transgression. Between 10.5-8 ka BP, the effects of sea-level rise started to influence the study area: groundwater rise resulted in the formation of extensive wetlands, fluvial flood basins became more frequently flooded, sediment-aggradation rates increased and finally the river valley changed into an estuary with adjacent tidal basins. Sea level reached rates of 1 m/100 yr before 8 ka BP with a period of 2 m/100 yr between 8.5-8.3 ka BP as a result of sea-level jumping. During the latter period sea level rose 4.06 0.5 m: 1.95 0.74 m background sea-level rise and 2.11 0.89 m sea-level jump. This jump is linked to the drainage of Lakes Agassiz and Ojibway in the Hudson Bay area and linked to the 8.2 event. After 8 ka BP the rate of SLR slowed down to 0.6 m/100 yr. North and south of the estuary, retrogradation of the coastline occurred at a faster rate than near the mouth at Hoek van Holland, leading to the formation of a promontory. In the upper estuary a bay-head delta was formed. Around 7.3 ka BP the main branch of the Rhine connected to a tidal ...