History of Saharsa District states that earlier this district was within Bhagalpur Division. Kosi Division was formed on 2nd of October, 1972 consisting of Saharsa, Purnia and Katihar District with its head quarters at Saharsa. Similarly, a new Civil Sub-Division Birpur was created on 1st December 1972 consisting of 24 development blocks namely Raghopur, Chhatapur, Basantpur and Nirmali, which were previously under Supaul sub-division of this district. Two new districts Madhepura district and Supaul district have been formed from Saharsa District on 30th April, 1981. Saharsa District now consists of 2 sub-divisions, namely Saharsa Sadar and Simri Bakhtiarpur. The district consists of 10 development blocks and anchals each.
Saharsa District was created on 1st of April, 1954. Formerly it had no independent status and parts of Saharsa were included in the old districts of Munger district and Bhagalpur district. The district has been largely influenced by its geography. Some important historical objects or landmarks have been preserved in a few places and it is on the basis of these that some kind of a connected account of the early history of Saharsa District can be constructed.
According to the ancient history of Saharsa District, Vaishali was the strongest republic in northern portion of Bihar and beyond that; there is the famous territory of Anguttarap. There was a small Janpad, named Anga, in Anguttarap and it included a portion of the district of Shaharsa. Various sites of the district now completely eroded and destroyed mainly Biratpur, Budhiagarhi, Budhnaghat, Buddhadi, Pitahahi and Mathai are associated with Buddhism.
Both Anga and North Bihar (including Saharsa) continued to be independent till the early part of the sixth century BC. For some time Magadha remained an integral part of Anga. Soon the prosperity of Anga declined. Magadh Empire was growing rapidly and the Nandas and Mauryas brought the whole of Bihar under the sway of Magadhan rule.
Under the Gupta Empire (from 320 AD), entire North Bihar was consolidated as a province with its capital at Vaishali. Therefore, the forward province came to be known as Bhukti and the district came to be known as Vishaya. In North Bihar, there were two Bhuktis, namely Tirabhukti (practically the whole of North Bihar) and Pundravardhanbhukti (included a portion of Saharsa, Purnia and a portion of North Bengal).
After the decline of the Gupta Empire the political gap came to be utilized by all contemporary chiefs. Taking advantage of the situation the Varman Dynasty of Assam (Assam) extended their authority up to this region. The rule of Purnavarman over North Bihar included the present district of Saharsa. Rise of Harshavardhana in 7th century AD was an event of great importance. He brought under his sway the whole of Northern India. The Pala Dynasty of Bihar and Bengal (8th century) AD gave a stable administration to the district. As, the Kalchuris pressed South Bihar, the Palas apparently shifted to North Bihar and Saharsa have been their headquarters during the time of Vigraphapala-III. Quite a few villages in Saharsa District are associated with the names of Pala rulers and it was through this district that the Palas could establish contact with Nepal.
Further, history of Saharsa District also states that the establishment of the Karnata in Mithila dynasty and the Sena dynastiy in Bengal followed the decline of the Pala authority in Bihar and Bengal. Both the Kanrnatas and Senas claimed authority over portion of Saharsa and often entered into armed conflict. After the fall of Oinwaras, there was virtual chaos. The Gandhaviya Rajputs are said to have acquired power and ruled during this period of confusion.
In 1764, Saharsa passed with the rest of Bengal under the Control of British East India Company. The district played a prominent role in the subsequent events which continued till the country`s independence.
