Knight (chess) king); in descriptive chess notation, "Kt" is sometimes used instead, mainly in older literature. In chess problems and endgame studies, the letter "S", standing for the German name for the piece, "Springer", is often used (and in some variants of fairy chess "N" is used for the popular fairy chess piece, the nightrider). Even among sets of the standard Staunton pattern, the style of the pieces varies. The knights vary considerably. Here are some examples. The knight, along with the king and the rook, has the oldest defined movement of any chess piece, its movement being unchanged since the invention
Empress (chess) attacking archbishop two squares diagonally away), while the rook+knight compound cannot. Worse, the word empress suggests a piece stronger than the queen, while this piece is at best equal to and perhaps weaker than the queen, especially in the endgame. The empress was first used in Turkish Great Chess, a large medieval variant of chess, where it was called the "war machine" (dabbabah; not to be confused with the piece more commonly referred to as the dabbaba today, which is the (2,0) leaper). It was introduced in the West with Carrera's chess from 1617, where it was called a "champion",