Abstract The purpose of this article is to provide a viewpoint of the development of the field of Discrete Event Systems (DES). Necessarily incomplete, because of the breath of topics and richness of research results, this paper is mainly presented from a System Theory-Automatic Control (AC) perspective. Written with a certain emphasis at the dawn of the discipline, the following five articles of this special section of the journal provide essential complements on its evolution along the four last decades. Starting with the identification of three basic threads along which many developments took place, the multidisciplinary and dynamic character of DES and the diversity of formalisms and techniques that are used are stressed.