The or Warring States Period, was a time when Japan was in civil war and the demand for ninja was high. This moment in history was the time of many of famous ninja, including Hattori Hanzō. But after the war resolved, their services were cut in a united Japan and, ninja began to fade into history. The Warring States Period (simplified Chinese: 战国时代; traditional Chinese: 戰國時代; pinyin: Zhànguó Shídài) is also a period in Chinese History with the Chinese Empire split in to various warring city-states led by numerous warlords. It followed the Spring and Autumn period and concluded with the victory of the state of Qin in 221 BC; creating a unified China under the Qin Dynasty.