Herat is the third biggest town of Afghanistan after Kabul and Kandahar. When Alexander the Great conquered this part of the Persian Empire, he renamed it Aria Alexandria, to make it his own. It was an important stage town of the Silk Road and benefited from the passage of the Hari River. While the city became famous under Alexander the Great, it is actually far older, back to the Achaemenid Empire, 6th century BC.