The Italian parametric earthquake catalogue is the result of several decades of historical seismological research, based in its turn on a centuries-long tradition of descriptive earthquake compilations. Thanks to historical seismological research undertaken since the mid-1980s, knowledge of the major historical earthquakes in Italy has hugely improved. These studies, however, focused mainly on earthquakes already recorded in Mario Baratta’s extensive compilation I terremoti d’Italia (a summary of earlier descriptive earthquake studies, published in 1901), rather than on the identification of earthquakes still ‘unknown’ to the Italian seismological tradition.As the results of a systematic perusal of ‘serial’ historical sources show, it is still possible to discover locally significant earthquakes (i.e.important for improving seismic history and hazard assessment of given localities or areas) that no previous studies had ever considered. Initiating new research projects specifically aimed at the identification of earthquakes unknown to the seismological tradition is therefore essential to improve hazard assessments on a subregional and local level.