North Korea, officially the Democratic People's Republic of Korea, is a country in East Asia, in the northern part of the Korean Peninsula. The name Korea is derived from Goryeo, a dynasty which ruled in the Middle Ages. The capital and largest city is Pyongyang. North Korea shares a land border with China to the north and north-west, along the Amnok and Tumen rivers. A small section of the Tumen River also forms North Korea's short border with Russia to the northeast. The Korean Demilitarized Zone marks the boundary between North Korea and South Korea. The legitimacy of this border is not accepted by either side, as both states claim to be the legitimate government of the entire peninsula.
The Korean Peninsula was governed by the Korean Empire from the late 19th century to the early 20th century, until it was annexed by the Empire of Japan in 1910. After the surrender of Japan at the end of World War II, Japanese rule ceased. The Korean Peninsula was divided into two occupied zones in 1945, with the northern part of the peninsula occupied by the Soviet Union and the southern portion by the United States.