The Sengoku period, also known as Sengoku Jidai is the period in Japanese history in which civil wars and social upheavals took place almost continuously in the 15th and 16th centuries. Although the Kyōtoku incident (1454), Ōnin War (1467) or Meiō incident (1493) are generally chosen as the Sengoku period's start date, there are many competing historiographies for its end date, ranging from 1568, the date of Oda Nobunaga's march on Kyoto, to the suppression of the Shimabara Rebellion in 1638, deep into what is traditionally considered the Edo period. Regardless of the dates chosen, the Sengoku period overlaps substantially with the Muromachi period (1336–1573).

The first human inhabitants of the Japanese archipelago have been traced to the Paleolithic, around 38–39,000 years ago. The Jōmon period, named after its cord-marked pottery, was followed by the Yayoi period in the first millennium BC when new inventions were introduced from Asia. During this period, the first known written reference to Japan was recorded in the Chinese Book of Han in the first century AD.