In 1815 he was with the emperor Alexander in Paris, and attempted in vain to save the life of his old commander Ney. This almost cost him his position in the Russian service, but he succeeded in making head against his enemies, and took part in the congress of Vienna. Resuming, after a period of several years of retirement and literary work, his post in the Russian army, he was about 1823 made a full general, and thenceforward until his retirement in 1829 he was principally employed in the military education of the tsarevich Nicholas (afterwards emperor) and in the organization of the Russian staff college, which was opened in 1832 and still bears its original name of the Nicholas academy. In 1828 he was employed in the field in the Russo-Turkish War, and at the siege of Varna he was given the grand cordon of the Alexander order. This was his last active service. In 1829 he settled at Brussels where he chiefly lived for the next thirty years. In 1853, after trying without success to bring about a political understanding between France and Russia, Jomini was called to St Petersburg to act as a military adviser to the tsar during the Crimean War. He returned to Brussels on the conclusion of peace in 1856 and some years afterwards settled at Passy near Paris. He was busily employed up to the end of his life in writing treatises, pamphlets and open letters on subjects of military art and history, and in 1859 he was asked by Napoleon III. to furnish a plan of campaign in the Italian War. One of his last essays dealt with the war of 1866 and the influence of the breech-loading rifle, and he died at Passy on the 24th of March 1869 only a year before the Franco-German War. Thus one of the earliest of the great military theorists lived to speculate on the tactics of the present day. Amongst his numerous works the principal, besides the _Traité_, are: _Histoire critique et militaire des campagnes de la Révolution_ (1806; new ed. 1819-1824); _Vie politique et militaire de Napoléon racontée par lui-même_ (1827) and, perhaps the best known of all his publications, the theoretical _Précis de l'art de la guerre_ (1836). See Ferdinand Lecomte, _Le Général Jomini, sa vie et ses écrits_ (1861; new ed. 1888); C. A. Saint-Beuve, _Le Général Jomini_ (1869); A. Pascal, _Observations historiques sur la vie, &c., du général Jomini_ (1842).