diffusion, traditions do connect Gesar with the former Kingdom of Ling (). In Tibetan, gling means "island" but can have, as with the Sanskrit word dvīpa, the secondary meaning of "continent". Ling was a petty kingdom located in Kham between the Yangtze and Yalong River. The Gsumge Mani Stone Castle located near the source of Yalong River houses a shrine dedicated to Gesar at its centre. An historical kingdom of Lingtsang () existed until the 20th century. Growth of the Epic The success of the Turk Fromo Kesaro, whose name is a Persian pronunciation of "Rome (Byzantium) Caesar", in overwhelming an intrusive Arab army in Gandhara sometime between 739 and 745, may have formed the historic core behind the Gesar epic in Tibet. In the records of the earliest rulers of Ladakh, Baltistan and Gilgit, whose countries were later overrun by incursive Tibetans, royal ancestry is connected to the Bactrian Gesar. In its distinctive Tibetan form, the epic appears to date from the time of the second transmission of Buddhism to Tibet marked by the formation of the Sarma or "new schools" of Tibetan Buddhism, although the story includes early elements taken from Indian tantricism. The oral tradition of this epic is most prominent in the two remote areas associated with the pre-Buddhist ethnic religion known as Bon (Ladakh and Zanskar in the far west of Tibet and Kham and Amdo in the east), strongly suggesting that the story has native roots. However, the oral versions known to us today are not, according to R. A. Stein, earlier than the written versions, but rather depend on them. As an oral tradition, a large number of variants have always existed, and no canonical text can be written. However, the epic narrative was certainly in something similar to its present form by the 15th century at the latest as shown by the mentions in the rLangs-kyi Po-ti bSe-ru by Byang chub rgyal mtshan. Despite the age of the tradition, the oldest extant text of the epic is actually the Mongolian woodblock print commissioned by the Kangxi Emperor of Qing China in 1716. None of the Tibetan texts that have come down to us are earlier than the 18th century, although they are likely based on older texts that have not survived. In the late 19th and early 20th centuries a woodblock printing of the story was compiled by a scholar-monk from Ling-tsang,