The Real Spanish Academy and the Academies Association of the Spanish Language have a debt with the society to construct a dictionary of this type. The Spanish is the only western language that lacks an historical dictionary, essential instrument for the work of the Hispanists, as well as for the knowledge that Spanish-speaker have to have of their language.

The Investigation Institute of Rafael Lapesa, created by the Real Academy for making this new dictionary NDHLE, with the help of the lexicographical bases Corpus diacrónico del español (CORDE) and Corpus de referencia del español actual (CREATES) will face up to its beginning immediately.
In this project will work an equipment of about twenty philologists, aside from other ones from universities and other research centers.
To carry out this dictionary is a task of a great spread since as it supposes the application to texts of the past of the Linguistic's methods and the Philology's techniques. Both of themr will facilitate not only to obtain the coherence in the field of the definitions, but also to establish the relation between the lexical units through history.

It is considered an opened work and progressively perfect, as much in the sense to be adding new entrances like in reviewing the already existing ones.

The presentation of the NDHLE through Internet will allow by a side that the scientific community has a easy way of this work, as well as they take part in its improvement.