Determining the actual locations of the different places in the Mahabharata is an enigma that has fascinated me for a long time. I will hereby discuss the important places, their location and a brief history of each. I am starting with the Eastern states.
The five major states in Eastern India were Anga, Vanga, Pundra, Kalinga and Sumha. According to the Mahabharata, these kingdoms were named after their founders, the five sons of queen Sudeshna, wife of the Asura king Vali (One shouldn't confuse this Sudeshna with King Virata's wife.).
Based on Mahabharata evidence, the kingdom of the Angas roughly corresponded to the region of Bhagalpur and Munger in Bihar and parts of Bengal; later extended to include most of Bengal. River Champa (modern Chandan) formed the boundaries between the Magadha in the west and Anga in the east. Anga was bounded by river Koshi on the north. The capital of Anga was Champa, located on the right bank of river Ganga near its junction with river Champa. The relics of actual site of ancient Champa are stated to still exist near Bhagalpur in Bihar in the names of two villages called Champanagara and Champapura. Champa was noted for its wealth and commerce. It was also a great center of trade and commerce and its merchants regularly sailed to distant Suvarna-bhumi for trading purposes. The ancient name of region and kingdom of Champa of central Vietnam (Lin-yi in Chinese records) apparently has its origin in this East Indian Champa. Other important cities of Anga are said to be Assapura, Malini and Bhadrika.
Karna was made the king of this state as a gift from Duroydhana, and during his conquests he subjugated the other Anga kings; who later participated in the war on Duryodhana's side. Lomapada, Chitraratha, Vrihadratha, Vasuhoma and Dhadhivahana were among famous rulers of Anga.
Vanga was most likely located in modern Bangladesh, in the East of the Bhagirathi-Hooghly. The rulers of Vanga were vanquished by Bheema, Karna and Arjuna during their respective conquests. Sabhaparava of Mahabharata (II.44.9) mentions Anga and Vanga as forming one country. Apparently parts of the region were dominated by the kingdoms of Anga, Pragjyotisha and Magadha. They sided with Duryodhana in the Kurukshetra War and were described as remarkably skilled in Elephant warfare. Like Anga, it succumbed to the expanding Magadha Empire during the time of Bimbisara
The Pundra kingdom appears to have been located in modern day Purnia district in Bihar and parts of North Bengal, roughly bounded on the east by the river Kasataya (Koshi?), on the west by the modern Mahananda, which separates it from Anga, on the south by the modern Padma, and on the north by the hills, which were inhabited by aboriginal hill tribes. A king of the name Paundraka Vasudeva had great rivalry with Vasudeva Krishna and was later killed by him. The Pundras sided with Duryodhana at Kurukshetra.
Kalinga comprised of most of the modern state of Orissa, as well as some northern areas of the bordering state of Andhra Pradesh. It was a rich and fertile land that extended from the river Subarnarekha to Godavari and from Bay of Bengal to Amarkantak range in the West. Dantapura and Rajpura were two famous cities in this kingdom. Shrutayu, the king of Kalinga joined his forces with the Kaurava army and became a general; and was later killed by Bheema along with other princes from Kalinga. Later Kalinga became a republic and was noted for its maritime expeditions in South East Asia.
Suhma was the last of the five kingdms mythically linked to the legend of queen Sudeshna. It was situated roughly in South Bengal, West Bengal and gets a passing reference in the Mahabharata. It was not a very important state. Tamralipta, an ancient sea port and a copper mining site excavated near present day Tamluk, though mentioned as a sepaerate state probably had some links with Suhma. The latter was on an ancient trade route, and it bears evidence of human settlements since the Neolithic Age.
The only important North Eastern Kingdom mentioned in the Mahabharata was Pragjyotisha, situated probably in modern Assam. It was described as an Asura kingdom and Naraka, the king was strangely depicted as the son of an earth goddess. Naraka had a great battle with Krishna in which he and many of his demoniac allies perished. His son and successor Bhagadatta joined the Kaurava army, fought with valour and died at the hands of Krishna. The Naraka king mentioned at various places in Kalika Purana, Mahabharata and Ramayana covering a wide period of time were probably different rulers from the same dynasty.
Magadha was by far the most powerful and prosperous of all the Eastern Kingdoms and was situated in Southern Bihar, with its capital in Girivraja, near modern Rajgir. The kingdom was established by Brihadratha, who, according to legend, had his roots in the Chedi Kingdom of Central India and was the sixth in line from Emperor Kuru through his eldest son Sudhanush. Magadha rose to power during the reign of Brihadratha's son, Jarasandha who assumed the title 'Raj-chakravarti' and extended his empire across a large part of Eastern India. He brought together several powerful kings, including King Shishupala of Chedi, King Bhishmaka and Kamsa of Mathura along with many chieftains of Eastern India and set out to build an empire. It appears that under Jarasandha's leadership a strong anti-Krishna coalition was formed. As Jarasandha took control of a large part of Eastern India and pushed on his forces along the Gangetic Plains, several tribes succumbed, while many fled towards the West. After Kamsa's death he raided Mathura on several occasions and the Yadavas at last migrated to Dwaraka, at the Western fringes of India. Jarasandha was finally killed by Bheema in a wrestling duel and Magadha's hegemony soon ended. Jarasandha's son Sahadeva and Jayatsena, another Magadha king fought and died on the Pandava's side.
Magadha has a key role to play in the context of unraveling the historical facts associated with the Mahabharata, since it is only one of the two kingdoms of which the Puranas provide a chronological list of Kings upto historical times. Jarasandha's descendants were succeeded by kings from the Pradyota, Shishunaga, Haryanka, Nanda and Maurya dynasties respectively. Buddha's contemporary kings Bimbisara and Ajatasatru belonged to the Haryanka line and it is from about this time that we get a more or less continuous history of Magadha, as it started to emerge as a superpower.**********************************************************************************
Among less significant kingdoms of Eastern India, Sonita (located in Sonitpur, Assam and ruled by Banasura, its princess married Krishna's son Pradyumna), Odra (parts of Orissa) , Utkala (North Western Orissa) and Lauhitya (a Naga territory on the Brahmaputra basin, in parts of Assam and Arunachal Pradesh) may be mentioned.
It is debatable whether the Kurus and Panchalas of epic age had much contact with the kingdoms of the East and much of the descriptions are speculated to be later additions. But it is clear from the above discussion that these parts still maintained a decidedly non-Aryan, non-Vedic tradition. The legend of the five princes stated in the beginning, Bhagadatta's reference as a 'Yavana', the mention of an earlier Naga stronghold in Magadha and the repeated passages of the Mahabharata that renounce these people as Mlechchhas and Yavanas further reinforce this argument. Gradually though, with increasing contact such cultural disparities receded with time.
The map roughly depicts estimated locations of the seven kingdoms discussed. It is by no means accurate.