A detailed understanding of how the earth surface is being continuously shaped and why it looks the way it does are essential prerequisites for an appraisal of geomorphic processes and related changes in space and time. Data on the occurrence of past geomorphic events remains, however, scarce and predictions on how the expected climate change may affect the frequency and volume of earth-surface processes have to be based on limited datasets. Tree rings have on varied occasions proved to be a reliable tool for the acquisition of data on past events. In this article, examples are provided on how the recurrence of events can be assessed (how often?) or their timing determined with yearly and sometimes even monthly precision (when?). Based on the mapping of trees on the study site, it is also possible to determine the reach and lateral spread of events (how far?). Movement rates can be reconstructed (how fast?) or the magnitude of incidences assessed (how big?). In combination with meteorological, hydrological and/or seismological data, results from tree-ring studies can be consulted to identify triggers of previous events (why?).