Afghana or Avagana is a tribal chief or prince of Pashtuns, who is traditionally considered the progenitor of modern-day Pashtuns, the largest ethnic group in Afghanistan and second largest in Pakistan. The ethnonym "Afghan" is believed to derive from his name. Although historical records dispute this, as the earliest mention of the word Afghan is by Shapur I of the Sassanid Empire during the 3rd century CE, in documents found in Northern Afghanistan.