During the era of Chandragupta and Vindusara, Kalinga enjoyed its freedom as a separate and independent state, although it is not sure whether it was ruled by one king or as a group of kingdoms or any democratic form of government.
Ashoka and Kalinga Ashok (son of Vindusara) wanted to annex Kalinga with Magadha for commercial reasons, although some folktales indicates that he invaded for personal reason, but primarily commercial reason is most prominent. Because Kalinga has many sea ports which Magadha lacks and Kalinga is between north and south part of India and main trade routes goes through it, Ashok attacked Kalinga in 261 B.C. and an epic fight occurred between two armies near the river Daya. This site is now identified near Bhubaneswar, the capital city of Orissa. In this battle the Kalinga army put up a brave fight with Magadha’s mighty army. Although Ashok was winner at the end of the day, the bloodshed and human suffering changed his mind forever.
Ashok destroyed the old ruling structure of Kalinga and reorganized the territory.
After the war Kalinga become fifth province of Magadha empire. It seems Ashoka divided Kalinga into three sections having own headquarters.
Rock edits of Ashok are found in this administrative capital. Administration of Kalinga is almost similar to other Province of Magadha except that more humanitarian value is added to the same.
Almost immediately after the death of Ashoka, Kalinga broke away from the Mauryan Empire and claimed independence. As Mauryan rule ended, with it Buddhism also ended in Kalinga and most people reverted back to the traditional practice of Jainism.