in antiquity, the river was seen as the border between europe and asia. in the hebrew book of jubilees, it is mentioned as being part of the border, beginning with its westernmost point up to its mouth, between the allotment of japheth to the north and that of shem to the south, sons of noah. during the times of the old scythians it was known in greek as the tanaïs, and has been a major trading route ever since.