The Holocene continental hydrology, as revealed by a number of archives and proxies, fluctuates at all time scales, due to factors external or internal to the Earth system that control local, regional and global climates. Palaeohydrological reconstructions shed light on climate changes, on the history of human societies and on hydrological risk assessment. (C) 2004 Academie des sciences. Published by Elsevier SAS. All rights reserved.