Understanding the impact of fisheries on the commercial fish stocks requires detailed catch statistics and data on the dynamics of fleet and catch effort, at least before industrial fishing started. Most time series on the fleet dynamics start after the 1980s, at times when major changes in fleet characteristics had already taken place. In the present paper, the results of the integration of data on fleet size (from 1830), tonnage (from 1842) and engine power (kW, from 1912) of the Belgian sea fisheries fleet are presented. The decrease in fleet size and changes in overall tonnage and engine power since the beginning of the reconstructed time series, are quantified. The data show that the decrease in fleet size (-85%) and in overall engine power (-5%) was compensated by an increase in average tonnage per vessel (x10 increase) and in average engine power per vessel (x6 increase). The overall fishing effort of the fleet expressed as the total number of days spent at sea has decreased by approximately -84% between 1938 and 2010, while the average amount of fish landed per day per vessel (1,000 kg in 2008-2010) has at least doubled in the same period. The data reconstruction provides a unique view on the dynamics in the sea fisheries fleet of Belgium over 180 years and the political and social events associated to these changes.