The Indus Plains formed the most populous and richest satrapy of the Persian Achaemenid Empire, for almost two centuries, starting from the reign of Darius the Great (522-485 BCE). Its heritage influenced the region e.g. adoption of Aramaic script, which the Achaemenids used for the Persian language, but after the end of Achaemenid rule, other scripts became more popular, such as Kharosthi (derived from Aramaic) and Greek. The interaction between Hellenistic Greece and Budhism began when Alexander the Great overthrew the Achaemenid empire in 334 BCE, and marched eastwards. 
