I captured this from this wiki entry: https://simple.wikipedia.org/wiki/Shatranj
The Sanskrit names from Chaturanga name the four parts of the old Indian army: foot soldiers, cavalry, elephantry and chariotry. The Arabic name for the chariot prevailed in the English language until today, like for example the Arabic name for elephant prevailed in Spanish.
The form of a tower was developed when the game came to Europe. Elephant and Vizier would become bishop and queen. A paragraph about the bishop from another wiki page: https://en.wikipedia.org/wiki/Bishop_(chess)
"The canonical chessmen date back to the Staunton chess set of 1849. The piece's deep groove symbolizes a bishop's (or abbot's) mitre. Some have written that the groove originated from the original form of the piece, an elephant[22][23] with the groove representing the elephant's tusks.[24] The English apparently chose to call the piece a bishop because the projections at the top resembled a mitre.[25] This groove was interpreted differently in different countries as the game moved to Europe; in France, for example, the groove was taken to be a jester's cap, hence in France the bishop is called fou (jester) [26] and in Romania nebun (meaning crazy, but also jester).[27]"
I have also read- in connection with this set- that the bishop's mitre/fool's cap interpretations were made from the form of the rook piece, but given to what the elephant piece would become, i.e. what form symbolized the chariot was what became the bishop or le fou (the court jester).
Today, while i research Nishapur, I found that when chess was transmitted to Persia, the "Rook" became the "Castle" and the "elephant" became the "Bishop." The design of modern international chess seems to have inherited this mistake, but I don't understand Why was the name of the chess piece referred to as "Rook" changed back to "Rook" instead of continuing to refer to it as a "Castle"?Why was the "Bishop" not changed back to "Elephant"? What are the reasons for this naming convention in the context of chess?