 The craftsmen of these objects required refined skills in melting techniques, in the Lost-wax casting technique and acquired master skills of composition and execution for the elaborate engravings.Sources of prehistory and early history are mostly legends, which are passed on orally and, as time progresses, often mix with historical facts.The Legend of Thánh Gióng tells of a youth, who leads the Văn Lang kingdom to victory against the Chinese invaders, saves the country and goes straight to heaven.