The last one mentioned was known as Darayagan, named after the Achaemenid king Darius I (r. 550–486 BCE).[6] There are several versions of the how the city got captured; according to al-Tabari, during the siege, an Iranian defector named Sina (or Sinah) went to al-Nu'man and pleaded for his life to be spared in return for helping him how to show a way into the city. Al-Nu'man agreed, and Sina told him the following thing; "attack via the outlet of the water, and then you will conquer the city."[7]