Alexander overran the Achaemenid Empire in 331 BC and marched into what is now Afghanistan with an army of 50,000. His scribes do not mention Gandhara or Kamboja; instead, they name twelve small countries in those territories. This means that Gandhara and/or Kamboja must not have been very great kingdoms in the late 4th century BC. In 326 BC, most of these twelve or so countries that used to be in the Gandhara Kamboja Mahajanapadas were conquered by the Macedonian conqueror.