A Chinese legend concerning the pre-historic
Emperor Yu () tells of the Lo Shu, often in connection with the
Yellow River Map (Hetu) and the
eight trigrams. In ancient China there is a legend of a huge
deluge: the people offered sacrifices to the god of one of the flooding rivers, the Luo river (), to try to calm his anger. A magical
turtle emerged from the water with the curiously unnatural Lo Shu pattern on its shell: circular dots representing the integers one through nine are arranged in a three-by-three grid. Early records dated to 650 BCE are ambiguous, referring to a "river map", but clearly start to refer to a
magic square by 80 CE, and explicitly give an example of one since 570 CE.{{cite web | last=Swaney |first=Mark |title=Mark Swaney on the History of Magic Squares |url=http://www.netmastersinc.com/secrets/magic_squares.htm and the
Eight Trigrams, are all carried by a large turtle (that presumably stands for the
Dragon horse that had earlier revealed the trigrams to
Fu Xi). This example drawn by an anonymous Tibetan artist. ==The layout==