Sho Shogi (小将棋 'Small Chess') is a 16th century form of Shogi (Japanese Chess), and the immediate predecessor of the modern game. It was played on a 9x9 board with the same setup as in modern Shogi, except that an extra piece stood in front of the King: A 'Drunk Elephant' that promoted into what was effectively a second King. (While 9x9 may not seem 'small', it was smaller than the other Shogi variants prevalent at the time.) The Drunk Elephant was eliminated by the Emperor Go-Nara (reigned 1526-1557), and it is assumed that the drop rule was introduced at about the same time, giving rise to Shogi as we know it today.