The king is the most important piece on the chessboard, but is one of the weakest piece! The king is allowed to move only one square in any direction - up, down, left, or right, - ofcourse diagonally. The King captures the same way as it moves, and is only allowed to capture unprotected pieces on the chessboard. If a king tried to capture an enemy piece which had protection - that would be illegal as it would be putting the king in 'check'! (The king in danger). Refer to the diagram on the left side to understand better about the movement of the Kings.