Development of new kingdoms along the coasts:
(1) The southern half of the Indian subcontinent is marked by a long coastline, hills and plateaus, and river valleys. Kaveri valley is the most fertile.
(2) Chiefs and rulers who controlled the river valleys and the coasts became rich and powerful.
(3) Sangam poems mention the muvendar. This is a Tamil word meaning three chiefs, used for the heads of three ruling families, the Cholas, Cheras and Pandyas. They became powerful in south India around 2300 years ago.
(4) Each of the three chiefs had two centres of power: one inland, and one on the coast.