DYK #8: The king is defeated..

Checkmate  is a situation in chess, where one player's king is under threat and there is no way to meet that threat; i.e.: The king is under direct attack and cannot avoid being captured. Delivering checkmate is the ultimate goal in chess: a player who is checkmated loses the game.

Chess is a REALLY OLD GAME. The earliest evidence of chess dates back to the year 600 AD in Persia. "Shah" is the title of the royal Persian monarch, so naturally the King in chess was called the Shah. To win chess, you have to defeat the King, by attacking it and making it unable to move. This is called the "Checkmate" or "Shah Mat", literally, "The King is defeated". Mat is a Persian word for "defeated", "helpless", or "at a loss", all pretty good descriptions for a checkmated king.

Source: http://www.omg-facts.com/view/Facts/2650

 The reason that a player is said to have left with no legal moves when in 'checkmate' is due to the rule which says that a king could not be moved into check or left in check. This was to prevent 'capturing of the king' which was allowed in the Sanskrit variant of the game.

The Persian word for chess, shatranj, was probably derived from the Sanskrit chaturanga, the name of a chess-like game that was played on an eight-by-eight board.
Verification: http://en.wikipedia.org/wiki/Checkmate
Verification and more info on chess: http://www.metmuseum.org/en/exhibitions/listings/2011/the-game-of-kings-medieval-ivory-chessmen-from-the-isle-of-lewis/exhibition-blog/game-of-kings/blog/shah-mat