There is very little known about the creation of the Bishop. It probably represented the Pharaoh's spiritual counselor and adviser, a necessity in those days. With foot soldiers, a Knight, a Rook, and a Bishop, he had the basic forces necessary to wage war. For the battlefield, either giving very little thought to creating a playing field, or being unable to come up with a better idea, he used his checkerboard. Each army consisted of a Pharaoh, a Bishop, A Knight, a Rook, and four foot soldiers.
Some stories have the kings placed in the corners instead of on the fourth and fifth files.
It was during the 8th century in India, considered the birthplace of Chess, that the game evolved to sixteen pieces on a side. The Pharaoh's name was changed to King. Since there could only be one King on a side, and to keep the pieces symmetrical, another piece had to be created. Being more of an advisor rather than a warrior, he could only move diagonally one square at a time. Except for the Pawns, the Viceroy was the weakest piece on the board.