Sasanka is the most famous among the Kings of Gauda, but little is known of his early life and circumstances in which he came to acquire the throne of Bengal. It was possible that he started his career as a feudatory either under the later Guptas or under the Maukharis. At any rate he made himself the independent ruler of Gauda in the beginning of the 7th century A.D. His capital was Karnasuvarna. His rule extended over Northern and Western Bengal; whether it spread also over Eastern and Southern Bengal is not exactly known. It is probable that Magadha formed part of his dominions.
The most important event of his reign was the conflict with the Maukharis and the Pushyabhutis. He made an alliance with Devagupta of Malwa and fought against his enemies. He and his ally won initial success, defeated and killed Grahavarman Maukhari and took Kanauj into occupation. He is also said to have treacherously murdered Rajyavardhana, the Pushyabhuti king of Thaneswar. But his success did not last long. Rajyavardhana’s younger brother Harsha who succeed to the thrones of Thaneswar and Kanauj recovered Kanauj and began a protracted war with Sasanka. The details of the struggle are not known; but it is fairly clear that Sasanka ruled with undiminished glory till his death which occurred about 637-638 A.D.
Sasanka was a worshipper of Siva. Hiuen-Tsang describes him as a cruel persecutor of Buddhism. Several modern scholars have expressed the opinion that the persecution of the Buddhists was prompted by political and not religious considerations.
The greatness of Sasanka lies in the fact that he was the forerunner of the Imperials Palas who extended their authority over extensive portions of Northern India.