Ferz
The ferz or fers is a fairy chess piece that may move one square diagonally. It was used in orthodox chess and in shatranj before being replaced by the queen.
History and nomenclature
The ferz is a very old piece, appearing in chaturanga and shatranj, the ancestors of all chess variants; it also featured in games such as Tamerlane chess. The ferz was a standard chess piece until the modern moves of queen and bishop were developed around the 15th century, with the ferz being replaced by the former.The ferz also appears in some large historical shogi variants, such as in dai shogi under the name cat sword. The Thai variant of chess, makruk, retains the ferz from shatranj as the "Met", both as a starting piece and as the only pawn promotion option. Thus, much of shatranj endgame theory is also valid for makruk.
The piece was originally called the mantri, which was translated by the Persians to farzin or farzīn, which means "counsellor" or "wise man". This was shortened to ferz, and this became firz or fers in medieval Europe. Its name later changed to queen, but when that name started being used for the modern chess queen, its former name ferz or fers began to be used in chess problems. In modern Eastern Slavic languages, however, ferz is the current name for the chess queen.