All modern studies on chess genealogy agree that we can find the origins of chess in ancient India, when, in an indeterminate period around the 6th century during the Gupta Empire, the game called Chaturanga, was invented.
Chaturanga, literally means “the game of the four armies” and after its rapid diffusion in India and Persia during the 7th century, the game reached late medieval Europe and was transformed in the modern game of chess in the 15 century.
The “four armies” of Chaturanga are made of pieces similar to chess displayed on an 8×8 uncheckered board. The original and older version of this board game was called Chaturaji (“four kings”) , it’s for four players and each player has a Raja (King), a Yaanei (Elephant = Bishop), Iratham (Chariot = Rook), and ‘Kutharei (Horse= Knight ) And four Padàti (Foot-soldiers = Pawns); probably that’s why in modern chess have eight Pawns and two of each rook, knight and bishop.
The word rook of chess, for example, comes from Persian rokh which means chariot, and that’s how the Chaturanga’s piece was called in ancient Persia, this explains also why the rook in chess can move only on its horizontal axis or on his vertical axis because the chariot has the wheels and can’t jump or move in diagonal. The bishop of chess comes from the Elephant that in Chaturanga moves only two squares per time and the queen wasn’t a special piece like in modern chess, it only could move one square per time in order to protect the king.
Despite its old age Chaturanga is still played around the world especially in India and in the Middle East.