A republic in eastern Europe, located between Russia and the northern coast of the Black Sea. Ukraine was the heartland of medieval Russia and the center of the Kievan Rus state. Kiev dominated much of the territory of European Russia during the 9th-13th centuries, and it was through Kiev that Eastern Orthodox Christianity and the Cyrillic alphabet came to Russia. The 13th century Mongol invasion destroyed Kievan power, and for the next 400 years the country was dominated by Poland in the north and west and by the Tatar Khanate of the Crimea in the south. In 1654, Ukraine requested protection from Muscovy, and Russian conquest soon followed. During World War I, Ukraine was occupied by Germany, and in January 1918 an independent republic was declared. The local postmaster overprinted existing stocks of Russian stamps with the Ukrainian national emblem, the trident, creating hundreds of different stamps. During the Russian Civil War, Ukraine was the battleground of both Red and White armies, as well as Poland and the Allies. In 1920 it was reconstituted as a Soviet republic. Stamps were used by a variety of regimes in the region. Ukraine was again occupied during World War II, and the Hitler Head German definitive set, overprinted "Ukraine," was used. With the disintegration of the Soviet Union, Ukraine again became independent. Independence was declared August 24, 1991, and in December became a founding member of the Commonwealth of Independent States. Since regaining independence, Ukraine has faced hyperinflation and wrenching economic changes, as it attempts to liberalize its economy. It has disposed of its nuclear arsenal and reestablished its control over the Crimea, which had been transferred to Russian administration in 1954 and had become locally autonomous with the breakup of the Soviet Union. During the first year or two of Ukrainian independence, large numbers of overprints on Russian stamps appeared on the market, identified as locals. Patterned after the 1918 Trident overprints, most of these modern creations are bogus, created solely for sale to stamp collectors.