Why is the queen the most powerful piece in chess?

Because in the late 1400s, in Spain, players gave her a brand-new move. Before that, the piece next to the king was not a queen at all but a royal adviser, the vizier, and it was feeble: it could only step one square diagonally. The new rule let the queen sweep any distance in a straight line or diagonal, combining the rook and the bishop, and chess turned into the fast, sharp game we know.

Chess began in India as chaturanga, a war game whose four divisions of the army, infantry, cavalry, elephants and chariots, became our pawn, knight, bishop and rook. In Persia it became shatranj, and players there started calling "Shāh!" when they attacked the king and "Shāh Māt!", the king is helpless, when it could not escape: our checkmate. Through the Muslim world it reached Europe, where the vizier slowly turned into a queen; the first surviving mention of her as regina, Latin for queen, comes from a poem written around 997.

Medieval chess was slow, with many games lasting days. Then, around 1475 in Valencia, the queen's modern move appears in a Catalan poem, and the new version was nicknamed "Mad Queen Chess". Checkmates came faster and the rules spread across Europe. The change happened during the reign of Isabella I of Castile, and some historians think a real, very powerful queen may have helped inspire the board's most powerful piece.

The old name survives: Russian players still call the queen ferz, the Persian word for the vizier.