Jomini, Henry, Baron, the son of a Swiss magistrate, was born at Payerne, in the canton' of Vaud, in 1779. Though yearning for a military life, he entered a French bank, but the Swiss Revolution called him home, and at the age of nineteen he became Chief Secretary of War. In 1801 he returned to Paris, and Ney took him as his private secretary. His Traite des Grandes Operations Militaires, presented to Napoleon on the field of Austerlitz (1805), brought him into favourable notice, and when next year he published his essay on the prospect of a war with Prussia, the Emperor attached him to his person. After the Peace of Tilsit he was made chief of Ney's staff, but the jealousy of that general during the Spanish campaign of 1808 drove him to seek employment from the Tsar. Napoleon forbade this, and on his refusal to serve against Russia appointed him Governor of Wilna, in which capacity he did much to facilitate the retreat from Moscow. The Battle of Bautzen was won chiefly through his strategy, yet he failed to secure his share of the rewards, and he finally joined the Russian Army, assisting in the German campaigns, but declining to take part in the invasion of France. After 1815 he settled in Paris, where he produced his great works, Principles of Strateiy, History of the Campaigns of the Revolution, The Public and Mi-Utarg Life of Napoleon, etc. He served in the Turkish War of 1828, and superintended the military studies of the Tsarevitch, dying in Paris in 1869.