is the third largest island of Japan and most southwesterly of its four main islands. Its alternate ancient names include Kyūkoku, Chinzei (鎮西, “West of the Pacified Area”), and Tsukushi-no-shima . The historical regional name Saikaidō referred to Kyushu and its surrounding islands. In the 8th century Taihō Code reforms, Dazaifu was established as a special administrative term for the region. As of 2006, Kyushu has a population of 13,231,995 and covers 35,640 square kilometres .