Origins

The origins of the Karnats of Mithila (Karnas) lie within South India. Sena dynasty inscriptions refer to Nanyadeva as Karnata-Kulabhusana indicating that he had his origins in the South (Vatapi, Karnataka) and likely arrived in the North through the Chalukya invasions. His ancestors were petty chieftains and adventurers in Eastern India and Nanyadeva carved out his own kingdom in Mithila.^[15]

When Nanyadeva first arrived in the region in 1093 A.D., he originally established his stronghold in Nanapura in Champaran, Bihar and referred to himself as Mahashamantadhipati as confirmed by the local traditions of Mithila. The title suggests that he was likely originally a commander in the Chalukaya army. He later shifted his capital to Simraungadh.^[16]

Nanyadeva's reign

The reign of Nanyadeva can be precisely dated by an inscribed stone pillar at Simraungadh which says, translated into English, "In the Śaka year 1019, on Saturday, the 7th of śrāvaṇa, in the śvāti nakṣatra, king Nānyadeva took the land."^[17]: 234 This corresponds to a date of 10 July 1097 CE.^{[18]: 35 [note 1]}

The Mithila region had formerly belonged to the Kalachuris of Tripuri. At some point (probably c. 1122), the Kalachuri king Yashahkarna appears to have invaded in an attempt to recapture the territory. Based on the Berighati inscription, it seems that Yashahkarna's invasion caused significant devastation to the region but was ultimately unsuccessful, and after his retreat in 1124 or 1125, the Kalachuris made no more attempts to reconquer the region.^{[17]: 240–1}

Another event that happened during Nanyadeva's reign was a clash of some sort with the Sena ruler Vijayasena, possibly because both of them were trying to win territory in the east. The Deopara inscription, authored by the poet Umapatidhara under Vijayasena's direction, describes Nanyadeva as a "defeated hero" who Vijayasena took as a prisoner. It says nothing about Vijayasena conquering Mithila, though, so while he may have inflicted a major defeat on Nanyadeva, Nanyadeva remained an independent ruler. Whatever the exact nature of this event, it seems to have left Nanyadeva a "negligible factor in North Indian politics" compared to the Senas and Gahadavalas.^{[17]: 243–51}

At some point, possibly after the tussle with Vijayasena, Nanyadeva got involved in the Nepal region. According to Upendra Thakur, Nanyadeva may have championed Śivadeva, a prince of the Thakuri dynasty (which had been dethroned by another branch by around 1080), in his bid for the throne. By doing so, he expanded his own influence in Nepal.^[17]: 251 According to Sinha, the relationship between Nanyadeva and Śivadeva (who ruled between c. 1118 and 1123) is more uncertain – Nanyadeva may have supported Śivadeva, but they may have also been rivals.^[18]: 49 The nature of Nanyadeva's authority in Nepal is also unclear. According to Thakur, Nanyadeva probably had "a loose sort of hegemony over the princes of Nepal", with the local princes recognising his nominal suzerainty but otherwise remaining mostly independent.^{[17]: 252–3}

According to local tradition, Nanyadeva's original capital was at Nānyapura in the present-day Champaran districts of Bihar, where ruins are still visible. Nepalese tradition, on the other hand, says Nanyadeva had his capital at Simraungadh. Whenever the shift happened, Simraungadh went on to serve as the main capital for the later Karnat rulers, while Nānyapura ended up becoming abandoned, and no later traditions or documents mention it.^{[17]: 241, 51–2}

Nanyadeva also apparently wrote a commentary on the Nāṭyaśāstra.^[18]: 50

Downfall

Harisimhadeva (r. 1295 to 1324 CE), the sixth descendant of Nanyadeva was the last Karnat sovereign of Tirhut. During the later years of his reign, the Tughlaq dynasty came to power, which ruled the Delhi Sultanate and most of Northern India from 1320 to 1413 CE. In 1324 CE, the founder of the Tughlaq dynasty and Sultan of Delhi, Ghiyasuddin Tughlaq, turned his attention towards Bengal.^[19][14] The Tughlaq army invaded Bengal. On his way back to Delhi, the Sultan heard about Simraungarh, which was flourishing inside the jungle.^[20] Harisimhadeva turned out to be the last king of the Karnata dynasty as he didn't show his strength and left the fort when he heard the news of an army of the Tughlaq Sultan approaching Simraungarh.^[21] The Sultan and his troop stayed there for 3 days and cleared the dense forest. Finally on day 3, the army attacked and entered into the huge fort whose walls were tall and surrounded by 7 big ditches.^[22]

The remains are still scattered all over the Simroungarh region. The king Harisimha Deva fled northwards into what is now Nepal. The son of Harisimhadeva, Jagatsinghadeva, married the widow princess of Bhaktapur, Nayak Devi.^[23]

Later Karnats

After Harisimhadeva fled Mithila, evidence exists of Karnat Kings still ruling some parts of the region up to the 15th century during the same time when the Oiniwar dynasty controlled central Mithila. In Champaran, the ruler was Prithvisimhadeva and his successors including Madansimhadeva. Their territory extended up to Gorakhpur district. Prithvisimhadeva was considered to be a descendant of Harisimhadeva. Other remnants of the Karnat dynasty were also found in Saharsa and Madhepura districts, where inscriptions have been found that refer to a ruler called Sarvasimhadeva.^[29]

Descendants

It is said that after his defeat, Harisimhadeva fled to Kathmandu where his descendants became the founders of the Malla dynasty of Kathmandu. The Mallas were noted to be great patrons of the Maithili language.^[30]

It is also said that another branch of the Karnats remained in Mithila and their descendants became the Gandhavariya Rajputs of North Bihar who held many chiefdoms in the region.^[31][32]