Shatranj

Shatranj is a historical form of chess that was adopted and developed in Persia and spread widely through the Islamic world. It belongs to a very early stage of the game's history and became one of the crucial forms through which chess later reached Europe. It was played on an eight-by-eight board with a general piece arrangement broadly similar to modern chess.

Similar does not mean identical. The piece in the modern queen's place was the farzin, a counselor or vizier that could move only one square diagonally. Other pieces also had powers different from their modern counterparts. Castling, which now moves the king and a rook in one turn under specific conditions, did not yet exist in its modern form.

Medieval shatranj developed its own masters, analysis, and composed positions. Over the centuries, the rules changed. In Europe during the fifteenth century, the piece that became the queen gained its powerful modern movement; modern castling appeared later. Shatranj therefore shows that today's chess rules were the product of a long evolution rather than a single invention.