Chenla or Zhenla (; ចេនឡា, Chénla ceːnlaː; Chân Lạp) is the Chinese designation for the successor polity of the kingdom of Funan preceding the Khmer Empire that existed from around the late sixth to the early ninth century in Indochina. The name was still used in the 13th century by the Chinese envoy Zhou Daguan, author of The Customs of Cambodia. It appears on the Mao Kun map. However, modern historiography applies the name exclusively to the period from the late 6th to the early ninth century. This period of Cambodian history is known by historians as the Pre-Angkor period. It is doubted whether Chenla ever existed as a unitary kingdom, or if this is a misconception by Chinese chroniclers. Most modern historians assert that "Chenla" was in fact just a series of loose and temporary confederations of principalities in the pre-Angkor period. "Chenla" or "Zhenla" was the name given in Chinese accounts of an entity that sent tributes to Chinese emperors. The word "Chenla" or "Zhenla" and likewise Funan are unknown in the Old Khmer language. Folk etymology attempts to link Chenla (真臘) to a translation of its Chinese name as "Pure Beeswax", which was one of its regional commodities mentioned in Chinese annals. It has been suggested that the name means "Defeated Siam" as Zhenla has been reconstructed to Tsienliäp in Tang dynasty pronunciation, which is similar in sound to the Cambodian town Siem Reap whose name is often taken to mean "Flattened Siam". However, it has been pointed out that this derivation is problematic as conflicts between Siam and Cambodia occurred centuries after the name was first used. Therefore, although the names Chenla and Siem Reap could perhaps be related, Michael Vickery argued that the original meanings of both names are unknown. Similar explanation however may apply to a later variant form Zhanla (占臘); according to author Peter Harris: "It very likely means "Defeated Chams" since Zhan is the word in Chinese for Cham.