The  word Oriya  is an  anglicized version of Odia which itself is a modern name for the Odra or Udra  tribes that inhabited the central belt of  modern  Orissa. Orissa  has  also  been  the  home  of  the  Kalinga  and   Utkal  tribes  that  played  a  particularly  prominent
role  in  the  region's  history,  and  one  of  the  earliest  references   to  the  ancient  Kalingas  appears  in   the   writings  of  Vedic  chroniclers.  In  the  6th  BC.,  Vedic  Sutrakara   Baudhayana   mentions   Kalinga  as  being  beyond  the  Vedic  fold,  indicating that  Brahminical  influences  had  not  yet  touched  the  land. Unlike some other parts of  India,  tribal  customs  and  traditions  played  a  significant  role  in  shaping   political   structures  and  cultural  practices  right  up  to  the  15th  BC.  When  Brahminical   influences  triumphed  over  competing  traditions  and  caste  differentiation  began  to inhibit social mobility and erode what had survived of the ancient republican tradition.