Antoine-Henri Jomini was a Swiss military officer and historian born in 1779. He is best known for his contributions to military theory during the Napoleonic Wars. Jomini served in the armies of both Napoleon Bonaparte and the Russian Empire, where he gained valuable experience in warfare. Jomini's most significant work, "Summary of the Art of War," outlined key principles of military strategy and tactics. His ideas emphasized the importance of decisive battles and the use of terrain, influencing military leaders and theorists in the 19th and 20th centuries. Jomini passed away in 1869.