A player's light-square and dark-square bishops placed so that they occupy adjacent diagonals, creating a potent attack. Also called raking bishops, and sometimes Harrwitz bishops.

Bernhard Horwitz (1807 in Neustrelitz – 1885) was a German chess master and chess writer. "Horwitz bishops", a configuration in which two bishops are aggressively placed on adjacent diagonals, are named after Horwitz.