Japan is an archipelago of 6,852 islands. The four largest islands are Honshu, Hokkaido, Kyushu and Shikoku, together accounting for 97% of Japan’s land area. Most of the islands are mountainous, many volcanic; for example, Japan’s highest peak, Mount Fuji, is a volcano. Japan has the world’s tenth-largest population, with over 127 million people. The Greater Tokyo Area, which includes the de facto capital city of Tokyo and several surrounding prefectures, is the largest metropolitan area in the world, with over 30 million residents.
Archaeological research indicates that people were living on the islands of Japan as early as the Upper Palaeolithic period. The first written mention of Japan begins with brief appearances in Chinese history texts from the 1st century AD. Influence from the outside world followed by long periods of isolation has characterized Japan’s history. Since adopting its constitution in 1947, Japan has maintained a unitary constitutional monarchy with an emperor and an elected parliament called the Diet.
A major economic power, Japan has the world’s second-largest economy by nominal GDP (though recent government numbers from China claim China is now second) and the third largest in purchasing power parity. It is also the world’s fourth largest exporter and fifth largest importer. Although Japan has officially renounced its right to declare war, it maintains a modern and extensive military force in self-defence and peacekeeping roles. It is a developed country with very high living standards (11th highest HDI). After Singapore, Japan has the lowest homicide (including attempted homicide) rate in the world. Japan has the highest life expectancy of any country (according to both the UN and WHO estimates) and the third lowest infant mortality rate.