The Dutch Theatre Production Database is a historical database with data on theatre and dance productions in the Netherlands by professional Dutch and foreign producers and companies. The database contains data on practically all productions from 1940 up to now: over one hundred thousand productions that can be freely searched using either the Webopac (http://theatercollectie.uva.nl/search/advanced) or the website Theaterencyclopedie (https://theaterencyclopedie.nl). Since 2013 the database is managed by the Department of Special Collections of the Library of the University of Amsterdam. It is the only source that offers an overview of the complete theatre programme in the Netherlands. The origins of its development lie in the card catalogue of the library of the Toneelmuseum of the 1960s. The database itself is now nearly three decades old and has grown much larger than the first compilers could ever have imagined. Until now a history of its development has been lacking. This paper offers a reconstruction of the history of the creation and development of the data and a description of the protocols and input system. This paper clarifies which sources have fed the database and which systems and productions have been fed by the database. With this paper, the verifiability and representativeness of the data can be assessed more effectively.