Heian shōgi (平安将棋 "Heian era shogi") is a predecessor of modern shogi. Some form of the game of Chaturanga, the ancestor of both chess and shogi, reached Japan by the 9th century, if not earlier,[1] but the earliest surviving Japanese description of the rules dates from the early 12th century (c. 1120, during the Heian period). Unfortunately, this description does not give enough information to actually play the game, but this has not stopped people from attempting to reconstruct this early form of shogi.