Khagaria was a part of the district of Munger, as a subdivision. The sub-division of Khagaria was created in the Year 1943-44. It was upgraded as district, with effect from 10th May, 1981, vide Government of Bihar notification no. 7/T-1-207/79 dated 30th April,1981. As a sub-division of the old district of Munger, Khagaria was the youngest, in terms of creation of subdivision, before independence. The other three older subdivision were Munger sadar, Begusarai and Jamui. The Jamui sub-division was created on 22nd July,1864 and Begusarai sub-division on the 14th February 1870.
Khagaria was created as a separate sub-division mainly because of the difficulties arising out of a lack of easy means of communications. Railways were a very old means of communication in this district. As per the Gazetteer of 1960,this Sub-division had three railway lines – the north Eastern Railway, passing west to East had four Stations – Khagaria, Mansi, Maheshkhunt and Pasraha . One branch Line shot off from Khagaria passing through Olapur and Imli, while another branch line shot off from Mansi, which went up to Saharsa. This Mansi- Saharsa branch line, during that period was however disturbed during rains between Katyani Asthan and Koparia, a distance of 6 miles, which had to be covered by boats. Apart from railways, the other means of communication was roads, which were in a very bad shape. The only metalled road at that time was 22 mile long Maheshkhunt- Aguawani ghat road, which was still under construction. During that period Khagaria- Parihara- bakhri Road was also under construction and National Highway linking Moakamaghat to Assam was under contemplation.
Recurrence of floods was an annual affair, as five major rivers – The Ganga, The Gandak, The Bagmati, The Kamala and The Koshi passed through the area of the subdivision of Khagaria. The recurrence of floods along with water logging made communication extremely difficult in the rainy season. Before the construction of South embankment of Baghmati and Gogari- Narayanpur embankment, the vast portion of land between the railway line and three streams, namely, the Bagmati, the Kamla and The Ghaghri ( the main stream of Koshi) and the various streams, as the Maria river and the Maitha river, used to abound in marshes.
It is said that the entire area, now included in the district of khagaria, was “Dahnal”, affected by floods of the Ganga, the Gandak, the Kamla, the Bagmati and the Koshi and that because of its physical situation, any site of importance must have been washed away. That is why, it does not possess any historical site of importance. According to the history, commonly known in this part, it is said that during the time of Emperor Akbar, Raja Todarmal had been entrusted with the duty of making a survey of the entire area, but as he failed to do it, he advise that this area should be excluded, in other words, he adopted the policy of “Farak Kiya” and that is why the area is Known as “Pharkiya Pargana”.