This book accompanies an exhibition at the Louvre. It is dedicated to the life, career and scientific legacy of Breguet, the celebrated clockmaker, physicist and inventor. He a master in his art, solicited by the most exclusive clients of his time such as Marie-Antoinette, Napoleon, Josephine and Talleyrand. Breguet initiated modern watch-making by inventing a series of mechanisms patented in his name, which include the most famous tourbillon clock and the self-winding mechanism especially conceived for Marie-Antoinette. This most famous watch, finished after Marie-Antoinette's death only, had disappeared for centuries. It was found under mysterious circumstances a few weeks ago only and is represented for the first time in this book.