[18] According to the historian Upinder Singh, In the 4th century CE, Orissa was divided into several small principalities, some of which owed allegiance to the Guptas.

The Korni copper plate mentions that Kamarnava I came to the Mahendra mountain situated to the east of Gangawadi and then onwards to Kalinga.

It also states that Kamarnava I, the eldest son of Virasimha, had left Kolahalapura (Kuvalalapura or Kolar), the capital of Gangawadivisaya (Western Ganga kingdom in southern Karnataka) after giving up his rightful throne to his paternal uncle.

He set forth eastwards along with his four brothers to establish a new kingdom, reached and ascended the mountain summit of Mahendra, worshipped Shiva as God Gokarnaswamin or Gokarneswara, obtained the bull (Nandi) emblem, descended to the eastern side, defeated and killed the local tribal king Sabaraditya (Savaraditya) or Baladitya in battle and acquired the whole of Kalinga with the blessings of Gokarneswara.

Historian M. Somasekhara Sarma suggests that the Kadambas brought with them their family God Madhukeshwara into their new home Kalinga.

It appears that Kamarnava II built the temple of Madhukeshwara in Nagara at the instance of one of his feudatories and relatives, the Eastern Kadambas.

Historian G. R. Varma further suggests that the Eastern Ganga king Kamarnava II renovated the existing temple of Gokarneshwara before renaming it as Madhukeshwara.

Historian R. Subba Rao states that the God Madhukeswara of Kalinganagara was also called Jayanteswara (based on Vaijayanti or Banavasi town) or Gokarneshwara (Gokarna's Mahabaleshwar deity) in some of the inscriptions found in that temple.

His son Hastivarman found himself stuck between two Gupta feudal dynasties of Odisha, the Vigrahas of South Toshali and Mudgalas.

The dynasty though remaining to be a strong ruling family in ancient Odisha and North Andhra Pradesh continued to remain as vassal rulers under the central authority of the Bhauma-Kara dynasty which is proven by the fact that a smaller Eastern Ganga king belonging to the clan and named as Jayavarmadeva mentioned himself as the vassal of Sivakara Deva I in his Ganjam grant and by whose permission he gave away the grants.

It was during the rule of Anantavarman Vajrahasta V in the mid eleventh century that the clan started emerging as a major military power challenging the authority of the Somavanshi Dynasty at their northern frontiers and allying with their arch rivals the Kalchuris.

After a series of victories in battle and making land grants to three hundred Brahmin families in his kingdom, Vajrahasta V assumed the titles as Trikalingadhipati (lord of the three Kalingas) and Sakalakalingadhipati (lord of complete Kalinga) challenging the centralized authority of the Somavanshis and laying the foundation to an imperial era for the Eastern Gangas.

In the later years of the century, Devendravarman Rajaraja I defeated the Somavanshi king Mahasivagupta Janmenjaya II completely while challenging the Cholas in battle, along with establishing authority in the Vengi region.

[30] The identification of the father of Rajasundari is a matter of great controversy and some scholars like K. A. Nilakanta Sastri identify the king as Virarajendra Chola.

[31][32] After the sudden death of Rajaraja I, his underage sons Chodaganga Deva ascended the throne, losing the many parts of his ancestral kingdom to the Cholas who were now in an advantageous position.

In his Korni copper plate grant he mentions himself to be the lord of 99,000 war elephants which while counting military strength according to the ancient Gulma system of military divisions, puts his strength to a million men and half a million animals employed to his command.

Chodaganga was married to the daughter of this uncle and also had Tamil officers serving him during his lifelong affairs of war and administration.

Chodaganga Deva was a strong king and was the son of Rajaraja Devendravarman and grandson of Vajrahasta Anantavarman of the Imperial Gangas of Kalinganagara.

Mukhalingam near Srikakulam of Andhra Pradesh bordering Odisha has been identified as Kalinganagara, the capital of the early Eastern Gangas.

[41] His son Chodaganga Deva who ascended the throne at the age of five under the protection provide by one of his maternal uncles from the Chola family had to overcome multiple obstacles before securing Kalinga, Vengi, Utkala, Odra and parts of Bengal as one kingdom.

Rajaraja III ascended the throne in 1198 and did nothing to resist the Ghurid Empire Muslims of the Khalji dynasty of Bengal, who invaded Orissa in 1206.

Narasimhadeva I, the son of Anangabhima, invaded southern Bengal in 1243, defeated its Muslim ruler of the Delhi Sultanate, captured the capital (Gauda), and built the Sun Temple at Konark to commemorate his victory.

The "mad king," Bhanudeva IV, who succeeded him, left no inscriptions; his minister Kapilendra usurped the throne and founded the Suryavamsha dynasty in 1434–35.

But the Eastern Ganga coins were written using the symbols for the single digits, with the position of the number indicating the value such as tens or hundreds, thus effectively using the Zero-place holder system.

[50][51] By successfully defeating the invasion attempts of Muslim invaders, the Eastern Ganga Empire is attributed to have served as the conservatory of the Hindu religion, art and culture at a time when India's indigenous civilization was endangered through the large scale massacre of Hindus, plundering of cities, desecration and destruction of temples and forcible conversions of the Hindu populace.

[53] A branch of the Eastern Ganga dynasty survived as the kings of the Paralakhemundi state, currently part of the Gajapati district, Odisha.

Hattahamir Deb was overthrown in 1360 CE by Ramai Deva of the Chauhan dynasty who led the foundation of Patna state, while the tribal chieftains installed Saraju Gangadeb as the ruler of Bamanda region.