Circular Chess: Byzantine Shatranj (Arrumiya)

Historically known as Byzantine Chess or Shatranj al-Rumiya, this variant is played on a circular board of four concentric rings. It is notably documented in Kitab ash-Shatranj, the world’s first systematic treatise on chess strategy. By eliminating corners and creating a continuous path, this version challenged players to adapt their tactics to a circular flow, representing a sophisticated peak in medieval strategic thought across the Mediterranean and Islamic worlds.