[1][2] He defeated the Muslim forces of Bengal who constantly threatened the Eastern Ganga dynasty's rule over his kingdom of Kalinga from the times of his father Anangabhima Deva III.

One correct interpretation comes from the late medieval period work of Gangavashanucharitam compiled by Vasudeva Somayaji in the eighteenth century of the small princedom of the rulers who were the descendants of the Eastern Gangas in southern Odisha.

In one of the sections of this work, one of the court poets known as Vidyaranava has narrated that there were six kings by the name of Narasingha or Narasimha in the Ganga dynasty lineage before his time out of which the first was the son of Anangabhima Deva III and used to wear a long robe.

When he walked fast due to his aggressive nature, his long robe resembled a tail and hence the king came to be known as Langula Narasimha Deva.

[8] Besides this accurate historical evidence in sync with the Konark sun temple's multiple stone panel depictions of the king, there is no other existing evidence that support any of the other interpretations about the term 'Langula' as the name of the Narasingha Deva I. Narasingha Deva I is glorified in multiple phrases and sections of literary works by some of the poets of his time besides being eulogized in the inscriptions of Kendupatna, Asankhali, Kenduli, Sikhareswara Temple, Panjabi math and Sankarananda Math found in Odisha.

Poet Dimdima Jivadeva Acharaya in his work "Bhakti Bhagbata Mahakavyam" has praised him as a renowned warrior who was the only one to have destroyed the invading Delhi Sultanate.

After ascending the throne of Kalinga, Narasingha Deva marched with his grand army, aided by Paramadrideva, who was his Haihaya brother-in-law, towards Bengal in the years 1242–1243 CE.

[16] The Odia Army made a calculated move to northern Rarh, Gauda and Varendra, the subordinate territory of the Delhi Sultanate.

Lakhnor was the headquarters of Turko-Afghan expansionist operations in Bengal, consisting mainly of Rarh and Varendra subdivisions under direct authority of the Delhi Sultanate.

In his work known as Tabaqat-i-Nasiri, chronicler Minhaj-I-Siraj Juzani, who accompanied the Muslim forces, gives live accounts and a vivid picture of the war.

Gaining some initial success, the Muslim army followed the forces of Narasingha Deva who were on a tactical retreat at this point towards the frontier fort of Katasin (Contai in the Southern part of today's West Bengal) that was surrounded by jungles and thick cane-bushes and provided a strategic defence.

In a dramatic description of these events of slaughtering of a whole Muslim army by the Odia forces, the descendant of Langula Narasingha Deva, Narasingha Deva II in his Sanskrit bronze inscription of Kendupatna, mentioned; "Radha Varendra Yabani Nayanjanaasru, Pureya Dur Binibesita Kalima Srihi, Tadh Bipralamm Karayadrabhuta Nistaranga, Gangapi Nunamamuna Yamunadhunavut"The Ganga herself blackened for a great extent by the flood of tears which washed away the collyrium from the eyes of the Yavanis [Muslim women] of Radha and Varendra [west and north Bengal] whose husbands have been killed by Narasimha’s army.

The Muslim army was again resupplied and reinforced by the Delhi Sultanate on the appeal of lkhtiyar, who marched further into the Odishan territory and a battle ensued at Mandarana or Umurdan in today's Jahanabad subdivision of Hoogly district.

[citation needed] There is no record of any direct Muslim invasion of Odishan territory for at least the next hundred years, due to the aggressive military expeditions in Bengal by Narasingha Deva I.

Draksharama inscription of Kakatiya General Mallala Hemadi Reddy from the year 1237 CE show that they were able to claim some territory north of Godavari but were eventually halted, possibly due to the military might of the Ganga forces under the command of Lāñguḷā Narasinha Deva.

"Sva-Kara-Karavala-Kampita-Ganapati-Bhu-Senapati Gajabaji-Samaja -Rarajaja-Tanujatmaja-Sya Marici-Parasara- Acara- Vicara- Caturaviranara-Kesari Dharadhi-Pasya-Nyaya-Namra-Paripanthi-Prithlvipati Kirita-Kotimani-Ghrni-Sreni-Bhiru-Nita-Pada Saro Jasya-Samrajya-Bhiseka- Atrutha-Samvat-Sare"Narasingha Deva I is mentioned as Paramamahesvara, Durga-Putra and Purushottamaputra in the Chandrashekhera temple inscription.

An inscription at Kapilash temple built by him compares him to the Varaha avatar (incarnation) of Vishnu who saved and raised the Vedas and the world from the oceans of uncertainty.

This sacrifice by a twelve-year-old saved his father and all the other masons as Narasingha Deva I, on learning about the consequences of his severe orders, was resentful and spared their lives.

Due to this extended period of peace, tranquillity and presence of military might; religion, trade, literature and art flourished and attained new heights.

Numerous magnificent temples were constructed in this era, beginning with the Eastern Gangas, one of the most remarkable initial rulers of which was Langula Narasingha Deva.

[22] He continued the worship of the holy triad like his father combining the three important deities of Odisha at the time, i.e., Purushottama Jagannahta, Lingaraja Siva and Viraja Durga.