The Yan Emperor () or the Flame Emperor was a legendary ancient Chinese ruler in pre-dynastic times. Modern scholarship has identified the Sheep's Head Mountains (Yángtóu Shān) just north of Baoji in Shaanxi Province as his homeland and territory. A long debate has existed over whether or not the Yan Emperor was the same person as the legendary Shennong. An academic conference held in China in 2004 achieved general consensus that the Yan Emperor and Shennong were the same person. Another possibility is that the term "flame emperor" was a title, held by dynastic succession of tribal lords, with Shennong being known as Yandi perhaps posthumously. Accordingly, the term "flame emperors" would be generally more correct. The succession of these flame emperors, from Shennong, the first Yan Emperor, until the time of the last Yan Emperor's defeat by the Yellow Emperor, may have been some 500 years. Historical records No written records are known to exist from the era of Yan Emperor's reign. However, he and Shennong are mentioned in many of the classic works of ancient China. Yan literally means "flame", implying that Yan Emperor's people possibly uphold a symbol of fire as their tribal totems. K. C. Wu speculates that this appellation may be connected with the use of fire to clear the fields in slash and burn agriculture. In any case, it appears that agricultural innovations by Shennong and his descendants contributed to some sort of socioeconomic success that led them to style themselves as di (), rather than hou (), as in the case of lesser tribal leaders. At this time it appears that there were only the bare beginnings of written language, and that for record keeping a system of knotting strings (perhaps similar to quipu) was in use. The Zuo Zhuan states that in 525 BC, the descendants of Yan were recognized as long having been masters of fire and having used fire in their names. Yan Emperor was known as "Emperor of the South" Downfall The last Yan Emperor, Yuwang, met the end of his reign in the third of a series of three battles, known as the Battle of Banquan. The exact location of this battle is disputed among modern historians, due to multiple locations adopting the same name at various points through history. Possible candidates include Zhuolu County and Huailai County in Zhangjiakou, Hebei, Yanqing District in Beijing, Fugou County in