Yes, the ancient Persian civilization had a written language called Old Persian. Old Persian is a cuneiform script that was developed around the 6th century BC. It was used primarily for royal inscriptions and administrative documents, and it was the official language of the Achaemenid Empire. It is believed that the script is based on the Elamite cuneiform script, which was used in the region of present-day Iran and Iraq. Old Persian was eventually replaced by the Pahlavi script, which evolved into the modern Persian alphabet.