The Diccionario del Español Medieval electrónico (DEMel) provides a lemmatised and semantically pre-structured electronic data archive on medieval Spanish. The basis of the data collection is the digitised material archived in card indexes of the Diccionario del Español Medieval (DEM), which was discontinued at the end of 2007 for financial reasons. The DEM covers the history of the development of Spanish vocabulary between the 10th and the beginning of the 15th century on the basis of far more than 600 literary and non-literary works or collections of texts and documents.