From the Working Group on the History of Mechanical Engineering and Machines and Mechanisms (HiM3), which belongs to the Spanish Association of Mechanical Engineering (AEIM), one of our aims is to conduct a series of publications which will contribute to the understanding and recognition of the history of our profession. The University of Jaén (UJA) eagerly took up this challenge through its Department of Mechanical and Mining Engineering and UJA Editorial. The first outcome of that idea is the book you have before you, the first in the series, dedicated to some of the Luminaries in Mechanical Engineering in Spain. The scientist?s work, despite its impact in the development of society, does not usually get the acknowledgement it deserves. This is even more evident regarding the work of engineers, who decisively contribute to the improvement of the constant growth of the standards of living of humanity by making the technologies and material resources that people need accessible for all. Clearly, the fact that this first volume features these engineers and not others has nothing to do with varying degrees of importance, or with the neglect of so many engineers whose contributions were paramount for the development of mechanical engineering. Indeed, we intend to feature those in future publications.