Earliest text which mentions the pawn promotion rule My question is about the history of the pawn promotion rule (promotion to a queen). 


  What is the earliest existing text (authentic written document in any language) which mentions the pawn promotion rule?
According to H.J.R. Murray (in A History of Chess, 1913), the pawn promotion rule (specially named as 'shatpada' or six steps) is already found in the very first known ancestry of chess: chaturanga (an ancient indian four-handed dice game whose pieces were  King, Elephant, Chariot, Horse and Pawn for each one of the four armies). Chaturanga exists in this form at least since the 7th century of our era. The subsequent forms of games related to chaturanga, including our western chess, have employed several different ways to promote pawns through the centuries (only to queen - or similar, like vizir or counsellor; only if the pawn reaches the 8th row at selected ranks - for example not in the 'e', 'b' or 'g' files; only to a previously captured piece; only to the piece originally related to the rank; etc), but this feature has been always present.

A History of Chess - Page 70
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