king and rook be on the same rank. In reality, the original FIDE Laws from 1930 explicitly stated that castling must be done with a king and a rook on the same rank (traverse in French). It is unclear whether any historically published sets of rules would technically allow such a move. Nomenclature In most European languages, the term for castling is derived from the Persian rukh (e.g. rochieren, rochada, enroque), while queenside and kingside castling are referred to using the adjectives meaning "long" and "short" (or "big" and "small"), respectively. References Bibliography External links "Mate by Castling" game collection at Chessgames.com 16th century in chess Chess tactics Chess terminology Rules of chess