Richelieu, Armand Emmanuel du Plessis, duc de (ärmäNˈ ĕmänüĕlˈ dü plĕsēˈ dük də rēshəlyöˈ) [key], 1766–1822, French statesman. An émigré from the French Revolution, he served Russia as governor of Odessa (1803) and of the Crimea (1805). Made chief minister of France by King Louis XVIII after the Hundred Days (1815), he secured the quick payment by France of the indemnity imposed by the second Treaty of Paris (1815) and thus hastened the evacuation of occupation troops. In his domestic policy, Richelieu favored leniency toward the ex-revolutionists and Bonapartists, thus displeasing the ultraroyalists headed by the king's brother, the comte d'Artois (later King Charles X). In 1816 Richelieu persuaded the king to dissolve the extreme reactionary chamber of deputies (the so-called chambre introuvable ) rather than submit to its program. Richelieu resigned in 1818, but returned to power in 1820, after the murder of the duc de Berry caused the fall of Élie Decazes. His measures against the radicals were not sufficient to suit the ultraroyalists, who applied pressure on Louis XVIII and secured (1821) Richelieu's dismissal. With Richelieu's successor, the comte de Villèle, the ultraroyalists came into power.