Shatranj is the oldest known ancester of modern chess game.

The design of the pieces was based on a very old chess set dated to the 12th century found in Nishapur, Iran

The original names of pieces were: Shah (King), Firzan (Minister), Fil (Elephant), Faras (Horse for Knight), Rukh (no meaning for rook) and Baidaq (Soldiers for pawns).

Here is what you can read about Shatranj on Jean-Louis Cazaux Odyssey of Chess site:

Illustration of Shatranj piece in Thomas Hyde's book (Mandragorias, seu, Historia shahiludii, 1694)

"Within 638-651, Muslim troops defeated and conquered the Persian empire. There, they soon assimilated the culture of their ennemies. The Persian elite adopted Islam and, in return, they were very important contributors to the bright civilization that shone from Middle East. Chess is a good example of that success. The Arabs learned Chatrang that became Shatranj after a phonetic evolution from Persian to Arabic. They brought Shatranj to the level of science, publishing several treatises of problems (mansubat) and openings (ta'biyat).

Al-Adli (800-870), ar-Razi (dead <900), as-Suli (854-946), al-Lajlaj (900-970), where among the best players of their time, living and becoming famous at Caliphs court in Baghdad. Al-Ya‘qûbî (dead in 907), at-Tabarî (838-923), al-Masûdî (circa 940-950), Daqîqî (dead in 975), Firdawsî (circa 1010), ath-Tha'âlibî (961-1038), al-Bêrûnî (973-1048), Mahmud al-Amulî (dead in 1352) are also famous Muslim authors and intellectuals who wrote about the game."