The word “Checkmate” in Chess comes from the Persian phrase “Shah Mat,” which means” the King is dead.”
Personal Comment: I wonder when the Persian phrase could have been used last.
The Iranian monarchy was dissolved in 1979 and the last two emperors were forcibly removed, not killed and did not die in office. When both men passed away they were no longer kings but exiled former monarchs and hence it could not be said, 'the king is dead'.