The names of the three dynasties , Cholas , Pandyas , and Keralaputras or Cheras are mentioned in the Pillars of Ashoka ( inscribed 273 -- 232 BCE ) inscriptions , where they are mentioned among the kingdoms , which though not subject to Ashoka , were on friendly terms with him . The names of the three dynasties , Cholas , Pandyas , and Cheras are mentioned in the Pillars of Ashoka ( inscribed 273 â `` 232 BCE ) inscriptions , among the kingdoms , which though not subject to Ashoka , were on friendly terms with him .