Checkmate — the word called out at the deciding moment of a chess game — carries within it the fate of a king. The roots of chess reach all the way back to Persia, where the king was called shah and "to become helpless, to be left powerless" was mat. When you cornered your opponent's king so it could no longer escape, you declared "shah mat" — "the king is helpless." Passing through the Arab world into Europe, the phrase shifted in pronunciation and became checkmate. The first part, check, likewise comes from that same shah ("king"), naming the moment a king is threatened. So a single game of chess casts the shadow of a Persian king who has traveled across a thousand years.