Koryo (918–1392) and Choson (1392–1910) were the last two Korean dynasties. Korean immigrants and their descendants in Russia, China, and Japan use the names of those dynasties as a reference for their ethnicity. Despite the continued use of Choson as a self-name in North Korea, the Japanese convention of referring to the Korean nation by that name (pronounced Chosen in Japanese) can be offensive to South Koreans because of its evocation of Japanese colonization of the nation (1910–1945).
Koreans share a common culture, but a sense of regionalism exists between northerners and southerners and between southeasterners and south westerners in terms of customs and perceived personality characteristics. Some suggest that this regionalism dates back to Three Kingdoms of Koguryo (37 B.C.E. –668 C.E.), Silla (57 B.C.E. –935 C.E. ), and Paekche (18 B.C.E. –660 C.E. ). In South Korea politicized regionalism has emerged between the southeastern (Kyongsang Province) and southwestern regions (Cholla Province) since the late 1960s as a result of an uneven pattern of development that benefits people in the southeast.
L South Korea occupies the southern half of the Korean peninsula, which protrudes about 620 miles (1,000 kilometers) southward from the Eurasian landmass between Soviet Siberia in the northeast and Chinese Manchuria to the north. About three thousand islands belong to Korea, among which the Province of Cheju Island is the largest. The total area of the peninsula, including the islands, is about 85,000 square miles (222,000 square kilometers), of which about 45 percent or about 38,000 square miles (99,000 square kilometers) constitutes the territory of South Korea.
Geopolitically, the peninsula is surrounded on three sides by the sea and by Russia, China, and Japan. Korea has suffered from the attempts of these neighboring countries to dominate it, particularly in the twentieth century. Each of them considers Korea to be of