Shatranj chess in Islam Chess quickly spread westward from India. The game entered Persia by the late 6th century, which is confirmed by the reference to chatrang the Persian name for chess, in the Karnamak-i-Artakhsher-i Papakan, written about 600 A.D.. This Persian work mentions the accomplishments of a Persian ruler, Ardashir, who had mastered the sports of hunting, horsemanship, ball-play, and chatrang. The mention of chess in the Karnamak is the oldest reference to chess anywhere. It also shows that the chess game that moved west from India became a noble accomplishment. This is in contrast to the status of chess in the Far East, where it is played by the masses. Perhaps owing to chess's establishment among the conservative upper-classes, the game changed little for the next nine hundred years. The Persians introduced the terms check and checkmate, which they called shah and shah mat. Shah is the word for the Persian king. Mat means 'defeated'. They also started using the term Rukh for the chariot. Rukh might once have meant chariot, though after chess entered Arabia, the original meaning was lost. To the Muslim players, and to many since, rukh or rook stood only for a piece on a chessboard. Not long after chess entered Persia, the Arab invasion of 640 A.D. occurred. Much of Persian culture was absorbed into the Arab Empire. Chess, called shatranj by the Arabs, was just one of the many acquisitions that the Muslims got from Persia. For instance, some stories of the Arabian Nights Entertainments, which like chess probably originated in India, passed through Persia to Arabia. In the regulated Muslim society, it was necessary to prove that chess was a permissible activity. There were those who said that chess was used for gambling, which was prohibited by the Qur'an. Even if chess was not a form of gambling, it was not specifically allowed by the Prophet (570?-632), who had dictated proper behavior in every phase of life. To justify chess, some Muslims wrote that chess was useful for training in military tactics. In Islamic literature, the attribution of chess-playing to important members of Muslim society, including the caliphs, may have been intended to help legitimatize chess. One story has the caliph Ali being told the popular Muslim legend that chess was invented to explain to a queen how her son was killed in combat. Upon hearing the tale, the caliph supposedly said, "There is nothing wrong with it; it has to do with war." Islam influenced the design of chessmen. The Sunnite branch of Islam, the orthodox Muslims, did not allow the representation of living forms in art. This was an application of the Second Commandment: "You shall not make a carved image for yourself nor the likeness of anything in the heavens above, or on the earth below, or in the waters under the earth." As a result, Islamic chessmen were (and continue to be) abstract. Islamic players were largely satisfied with shatranj and attempted few if any rule changes in the game. They instead concentrated on refining strategy. The Islamic players wrote extensively on the method of play and were the first to divide game analysis into openings, middle-game, and endgame. Islamic writers also compiled sample games and many mansuba. The Muslims were probably the best players of the old game. With so much theory developed for chess, the Muslim players did not want to change the rules, which would render much shatranj analysis useless. If an Islamic player became dissatisfied with shatranj, he was more likely to invent an entirely different chess variety to be played along side shatranj than to make something to supersede it. Many Islamic players did in fact create unusual chess games.