From Old to New Persian
This chapter looks at the long evolution of Persian, which is the only Iranian language to be substantially documented in all three periods of Old, Middle, and New Iranian on account of its close association with the main political centres for most of the time over the centuries: Old Persian with the Achaemenids, Middle Persian with the Sasanians, and New Persian with Islamic powers. The chapter ideally includes two parts, preceded by a brief survey of research on the three stages of the language.