Juan Carlos Martín Castillo is a Spanish author and popularizer, known for his work in the field of history and essays. He has published several books, among them "Cuando los genios andan sueltos" (When Geniuses Run Wild), a work that explores historical anecdotes and curiosities of great minds. He is a regular contributor to media outlets and participates in conferences, focusing on topics related to culture, history, and philosophy. His style is characterized by bringing knowledge to the public in an entertaining and accessible way.