Pragjyotisha (प्राग्ज्यॊतिष) or East Yotisha was an ancient Indian kingdom mentioned in the epics. According to later versions of the epic, King Bhagadatta or Bagadates I ruled the kingdom during the time of the Kurukshetra War where he met his death. In historical times, it came to be named as the Kamarupa Kingdom. Much of the mythical kingdom is culled from the 10th century Kalika Purana and the later Yogini Tantra. The kingdom roughly falls in modern-day Assam in India.
Rajatarangini tells us that Gopaditya, the king of Gandhara, in the hope of conquering Kashmira, had given shelter to the great grand-son of Yudhishthira. This exiled prince had a son named Meghavahana, whom his father sent to the country of East Yotisha to be present at the Sayamvara marriage of the daughter of its king who was a Vishnuvites and he had the fortune of being selected as the husband of the princess. He was also presented with an umbrella, which was got from Varuna by king Naraka and which cast its shade on none but a paramount king. This connection gave him some importance in the eyes of the people who believed that he would one day rise to power. And after his return with his wife to his father, the ministers of Kashmira invited him to accept the sceptre of their country, he being the descendant of their ancient king.
Rajatarangini tells that Lalitaditya, finding that almost all the kings had been conquered, turned towards the north, and had to fight his way with the haughty kings in that direction. He robbed the king of Kamvoja of his horses. In the mountains of Bhuskhāra the horses of the king became excited at the sight of the horse-faced women of the country. He thrice defeated Dussani and subdued him. He then conquered the Bouttas, and in whose naturally pale colored faces no further sign of anxiety was visible. He also conquered Darad. Here the soft wind charged with the scent of Raindeer cheered his army. Before he approached East Yotishapura, the inhabitants left that place. Here the king saw the forest in fire. His elephants then passed, through a sea of sand. Here was the kingdom of the females, and it was governed by a female and the soldiers became impatient for the women. The queen
[p.70]: submitted and came out to have an interview with the invader, and trembled before him, it is not certain whether with fear or in love. The people of North Kuru fled to the mountains for fear of Lalitaditya.
Tej Ram Sharma writes that the Allahabad pillar inscription of Samudragupta mentions Kamarupa (कामरूप) (L. 22) as one of the frontier states which were subordinate to Samudragupta and whose emperors paid him taxes and all kinds of obeisance. Majumdar  identifies it with Upper Assam. Kamarupa consisted of the Western districts of the Brahmaputra valley which being the most powerful state and being the first to be approached from the western side came to denote the whole valley.  The area of Kamarupa was estimated by the Chinese traveller Hiuen Tsang to have been 10,000 li i.e. 1667 miles in circuit which shows that it must have comprised the whole valley of Brahmaputra.  Saktisangama describes  Kamarupa as extending from Kalesvara to the Svetagiri and from Tripura to the Nila-parvata (which is the Niladri or Nilakuta, the name of the Kamakhya hill). According to the Yogini Tantra, the kingdom of Kamarupa included the whole of the Brahmaputra valley together with Rangpur and Cochbihar.  The Puranas mention Pragjyotisa, identified with Kamakhya or Gauhati, as the capital of Kamarupa.  The Kamauli grant of Vaidyadeva mentions Kamarupa as a Mandala of the Pragjyotisa-bhukti. 
Mentioned in Mahabharata
See List of Mahabharata people and places (II.31.9),(II.47.12), (II.47.14),(VI.83.9),(VI.112.59),
- Arjuna defeats Bhagadatta, the king of Pragjyotisha, during his military campaign to collect tribute for Pandava king Yudhisthira's Rajasuya sacrifice (2,26)
- An encounter took place between Bhagadatta and Arjuna for days together each desirous of victory over the other. Then Bhagadatta, who regarded Indra as his friend, made friendship with Arjuna. (5,168)
- King Bhagadatta of Pragjyotisha accompanied by all Mlechcha tribes inhabiting the marshy regions on the sea-shore; and many mountain kings came to attend Yudhisthira's Rajasuya sacrifice (2,33).
- The great warrior king Bhagadatta, the brave ruler of Pragjyotisha and the mighty sovereign of the mlechchas, at the head of a large number of Yavanas came to the Rajasuya sacrifice (2,50)
- The ruler of Pragjyotisha, the brave Bhagadatta is the foremost of those holding the elephant hook (skilled in fighting from the neck of a war-elephant) and is skilled also in fighting from a car. (5,168)
- Bhagadatta, the Pragyotisha king, fought in Kurukshetra War as a general under the Kaurava generallisimo Bhishma (6-65,75,82,84,96,112,114,115,117). He also fought under Drona another Kaurava generalissimo. (7-20,24,25,26,27). He was slain by Arjuna (7,27).
- After the Kurukshetra War, Arjuna fought a war with Bhagadatta's son Vajradatta, at Pragjyotisha, to collect tribute for Yudhisthira's Ashwamedha sacrifice. (14,75)
- By destroying the Mauravas and the Pashas, and slaying Nisunda and Naraka, Vasudeva Krishna hast again rendered safe the road to Pragjyotisha. (3,12)
- The Asuras had a city named Pragjyotisha, which was formidable, inaccessible and impregnable. It was there that the mighty Naraka, the son of the Earth (Bhumi), kept the jewelled ear-rings of Aditi, having brought them by force. Aditi's sons (the Devas) where unable to recover them. Beholding Krishna’s prowess and might, and weapon that is irresistible they employed him for the destruction of those Asuras. Krishna agreed to undertake that exceedingly difficult task. In the city of Nirmochana that hero slew six thousand Asuras, and cutting into pieces innumerable keen-edged shafts, he slew Mura and hosts of Rakshasas, and then entered that city called Pragjyotisha. It was there, that an encounter took place between the mighty’ Naraka and Krishna. Slain by Krishna, Naraka lay lifeless there. Having slain the Earth’s son (Bhumi-putra or Bhauma), Naraka and also Mura, and having recovered those jewelled ear-rings, Krishna came back, adorned with undying fame. (5,48). Mentioned also at (12,339)
- When Krishna went to Pragjyotisha, Naraka with all the Danavas did not succeed in seizing him there. (5,130)
- Vasudeva Krishna mentions that when he and his army was at Pragjyotisha, fighting there, Chedi king Sisupala, Krishna's cousin and enemy, came and burnt Dwaraka, the capital of Yadavas, in which Vasudeva Krishna belonged. (2,44)
- Salwa kings car of precious metals capable of going anywhere at will, bewildering all, reappeared at Pragjyotisha! (3,22)
In Jat history
P.161: It is stated that Mura was an Asura son of Kashyapa Prajaapati.91 He was the guardian of Pragjyotisha, the capital city of Narakasura. He had fenced the boundary of the capital city with 6,000 ropes, known in the Puranas as Mauravāsha.92 He goes to Mahameru, Identified with the Pamir mountains and challenges the Yakshas and Gandharvas to fight but none accepted the challenge, Thereafter Mura goes to Indra and challenges him to fight in his capital-Amravati with these words, "fight with me or leave this place". Indra did not fight and left Amravati and Mura ruled there for it long time. Ultimately Mura was killed by Krishna alongwith his overlord Narakasura.93 This attack on Amravati, capital of Indra, by Mura, finds support from Skanda Purana also where it is mentioned that the two warriors called Ugra and
91. Vamana Purana, chap, 6.
92. MBT, Sabha Parvan, chap. 38.
93. Bhagvata, X Skandha,
P.162 : Mayura attacked the capital of Indra. Here, as in the other Purana, the name of Mura is Sanskritised into Mayura, the reasons for which have already been discussed earlier. The second name Ugra, is again a tribal name, the Ugrians of Greek writers, and the present Uighur of Soviet Central Asia. The name of the ropes of Muraa, called Mourava ropes, is again the same as the name of the City and the clan, Maurav, as per Persian records. Thus the Mura and Naraka are identical with the Mura and Nairi of Assyriyan records, the present Mor and Nara clan of the Jats. This area was definitely in the west of India, rather in the northhwest and Pragjyotisha was its capital city. At the time of Mahabharata, it was ruled over by Bhagadatta who is called a king of Yavanas and also a king of Asuras. He was a friend of Pandu.94 He attended the Rajasuya sacrifice of Yudhisthira.95 Arjuna, defeats him in the North,96 and in the war he is killed by Arjuna.97 Vajradatta, son of Bhaga Datta was also killed by Arjuna.98 In Sabha Parvan both Mura and Naraka are stated to be rulers in the West.99
94. Sabha Parvan, op. cit., 14/14.
95. ibid., 51/14.
96. ibid., 26/7.
97. Drona Parvan,29/48.
98. Ashvamedha Parvan, chap. 76.
99. Sabha Parva 13/13. मुरं च नरकं चैव शास्ति यॊ यवनाधिपौ, अपर्यन्त बलॊ राजा परतीच्यां वरुणॊ यदा (II.13.13)
- Rajatarangini of Kalhana:Kings of Kashmira/Book II,p.33
- Rajatarangini of Kalhana:Kings of Kashmira/Book IV, pp.69-70
- Personal and geographical names in the Gupta inscriptions/Place-Names and their Suffixes, p.253-254
- The Vakatka-Gupta Age by R. C. Majumdar and A.S. Altekar. p. 142.
- The Ancient Geography of India by Alexander Cunningham. p. 500
- The Ancient Geography of India by Alexander Cunningham. p. 500
- Studies in the Geography of Ancient and Medieval India by D. C. Sircar. pp. 86-87 : Saktisangama Tantra, Book III, ch. VII, V. 10.
- Studies in the Geography of Ancient and Medieval India by D. C. Sircar., p. 87 : Historical Geography of Ancient India by B. C. Law. p. 226.
- Geographical Dictionary of Ancient and Medieval India by N. L. Dey. p. 87 ; Cities of Ancient India by B. N. Pur. pp. 85-88
- Epigraphia Indica. II, p. 353, LL. 48-49 ; Ethnic Settlements in Ancient India by S. B. Chaudhuri, p. 172.
- Jats the Ancient Rulers (A clan study)/Porus and the Mauryas,pp.161-162