The earliest predecessors of the game, chaturanga, originated in India in the 6th century AD, and spread from China to Japan, where it spawned a number of variants. Shogi in its present form was played as early as the 16th century, while a direct ancestor without the "drop rule" was recorded from 1210 in a historical document "Nichūreki," which is an edited copy of "Shōchūreki" and "Kaichūreki" from the late Heian period (~1120).