Antoine-Henri Jomini was a Swiss military theorist and writer, renowned for his seminal works on military strategy and tactics. Born on March 6, 1779, in the Valais region of Switzerland, Jomini served in the Swiss, French, and Russian armies during his career. His most famous works include 'The Art of War' and 'Vindications of the Conduct of the Campaigns of 1815'. He passed away on March 24, 1869.