Each year the Washington Map Society offers the Ristow Prize in honor of the late Dr. Walter W. Ristow, one of the nation’s premier map librarians and cartographic authors.  Dr. Ristow was for many years head of the Geography and Map Division at the Library of Congress and was the founding president of the Washington Map Society.

Luis A. Robles Macías, a PhD candidate in History at Université Libre de Bruxelles (Belgium), is the winner of the 2023 Dr. Walter W. Ristow Prize for Academic Achievement in the History of Cartography for his paper entitled "Polar Hemispheres: The Overlooked Alternative to Nautical Planispheres in Renaissance Iberia."  Luis obtained his engineering degree at the University of Seville and a Master of Science at the Institut Français du Pétrole (France) and McGill University (Canada) in 2001. He has since pursued a professional career in clean energy that has taken him to France, California, and Belgium. In parallel Luis became interested in the mathematical aspects of old maps and in the circulation of geographical knowledge in the Renaissance, which resulted in several academic publications. He eventually embarked on a PhD in History at the Université Libre de Bruxelles (Belgium), devoted to the life and works of sixteenth-century mapmaker Juan Vespucci. The defense of the thesis is scheduled for January 2024. Luis has been a scientific advisor to the MEDEA-Chart European research project on portolan charts and since 2020 is the editor of Maps in History, the magazine of the Brussels Map Circle.  His winning paper will be published in a future issue of The Portolan.