This map shows southeastern Europe during the Crimean War (1853−56) that pitted Russia against the Ottoman Empire (Turkey) and its allies Britain, France, and Sardinia. The western European powers backed the Turks in order to block Russia’s expansion into the Black Sea region, which they believed threatened their positions in the Middle East and the Mediterranean. Many of the war’s major battles were fought on the Crimean Peninsula in southern Russia, which, ironically, is not shown on this early map of the “theater of war.” The conflict ended with the Treaty of Paris, signed on March 30, 1856, in which Russia was forced to give up territory it had seized from the Ottomans. Color codes are used to indicate the Russian, Austrian, and Turkish Empires, as well as Greece, which had secured its independence from the Ottoman Empire in 1832, Moldavia, and the principalities of Wallachia (present-day Romania), Serbia, and Montenegro. The latter were territories nominally under Ottoman suzerainty, but which were autonomous and under Russian influence. The inset map at the lower left shows Constantinople (Istanbul), the Ottoman capital. A single distance scale is given, in kilometers, reflecting the standardization that came with increasing use of the metric system in the mid-19th century.