Chandragupta I was succeeded by his son, Samudragupta, who became the
ruler after subduing his rival, Kacha, an obscure prince of the dynasty.
  Written by Harisena, it gives a detailed account of the conquests of his
  royal master. This account contains a long list of states, kings and tribes
  which were conquered and brought under various degrees of subjugation.
  This list can be divided into four categories.
  The first one includes the 12 states of Dakshinapatha with the names of
  their kings, who were captured and then liberated and reinstated. They
  were Kosala, Pistapura, Kanchi, Vengi, Erandapalli, Devarashtra,
  Avamukta, Dusthalapura, Mahakantara, Kurala, Kothura and Palakka.
  The second one contains the names of the eight kings of Aryavarta who
  were exterminated.
  The third one consists of the rulers of forest states who were reduced to
  servitude and the chiefs of the five pratyantas or border states, and also
  nine tribal republics that were forced to pay all kinds of taxes, obey his
  orders and come to perform obeisance. The five border states were
  Samtata (East Bengal), Davaka (Assam), Kamarupa (Assam), Nepala, and
  Kartipura (Kashmir). The nine tribal republics were the Malavas,
  Arjunayanas, Yaudheyas, Madrakas, Abhiras, Prarjunas, Sarakinakas,
  Kavas, and Kharaparikas.
  The fourth one includes the Daivaputra Shahanushahs (Kushanas), Saka
  Murundas and the dwellers of Sinhala and all other islands who offered
  their own person for service to Samudragupta.
Aryavarta Campaigns It is certain that the campaigns in the Aryavarta,
undertaken with the purpose of the extermination of their kings, generally
preceded the subjugation of the adjoining territories.
    Several factors were responsible for the conquest of the Naga kingdoms.
Geo-political factors were the foremost. In the fourth century AD the Nagas
were, apart from the Guptas,