Contemporary newspapers and seismological literature describe in detail an earthquake occurred on December 31, 1948 in the Monti Reatini area (central Apennines, Italy). The seismic sequence that had this event as its main shock started in December 1948, went on for most of 1949 and was recorded in full by an unpublished regional earthquake catalogue compiled in 1980. However, none of the Italian parametric earthquake catalogues printed from the 1980s onwardsrecords either the December 31, 1948 earthquake or the earliest part of the 1948 - 1949 sequence. This paper describes how the “forgotten” event of December 31, 1948 was rediscovered and reinstated as one of the main quakes on record in the Monti Reatini area.