the Black King commands all of the adjoining squares, but he can only move to one of six of them and not to any one of the eight, as he could in diagram iii. He cannot move to K6 because his own Pawn occupies it and also because the White King could move into it were he alone on the board. Nor can the Black King move into Q6, because that also is a square within the range of movement of his adversary, or one of the eight squares commanded by the White King were he alone upon the board. Thus, the sphere of influence of the two Kings overlaps at K6 and Q6 with the result that those two squares are neutral territory, forbidden to both by the fundamental laws of Chess, for the Kings must always have an interval of at least one square between them.
As the object of the game is to capture or checkmate the adversary's King, it is readily seen that he is of paramount importance, and that the moves of all the other Pieces and Pawns are made with reference to him.
