Begusarai District occupies a central position in North Bihar. In 1870 it was established as a sub-divison of the Munger district. It emerged as a district in 1972. It was named after "Begu" a man of this district who used to look after "Sarai" an old and small market. Begusarai district is a part of Darbhanga division.
Begusarai lies in North Bihar between latitudes 25°15' and 25° 45' north and longitudes 85°45' and 86°36" east. This town expands perpendicularly from east to west which used to be a main link road. It is bounded on the north by Samastipur, on the south by the Ganga and the Lakhisarai district, on the east by Khagaria and Munger and on the west by the Samastipur and Patna districts.
The 2001 census count placed the Begusarai population at 23,42,989 as on the first of March. The population has grown at an annual average rate of 2.9%. There are many stages in the demographic transition beginning with a declining mortality and continuing fertility to a stage where both mortality and fertility rates decline more or less at the same rate and keep the population stable over a period of time.
The district Begusarai, an important district in the state of Bihar lies on the northern bank of river Ganga. Earlier it was a part of the greater Munger district. Begusarai district was carved out of it as a separate district on. 2nd October 1972 (A handnote on Begusarai district census-1991). Now it is a part of the Munger commissionery. Geographically, lying between latitudes 25015’N & 25014’N and longitudes 85045’E & 85045’E, it covers an area of 1918km 2. In the north, it shares its boundaries with Samastipur district; in the east and NE it is surrounded by Khagaria district. In the southeastern part lies the Munger district. In the south is Lakhisarai and in the southwestern side, along the banks of River Ganga, it is shares its boundaries with Patna district. It is situated in a part of Middle Gangetic plains, locally known as North Bihar plains. Administratively it is divided into five subdivisions- Begusarai, Teghara, Balia Manjhaul and Bakhri and eighteen blocks namely Begusarai, Mattihani, Teghra, Samho, Bachhwara, Barauni, Bhagwanpur, Balia, Sahibpur Kamal, CheriaBariarpur, Khudabandpur, Bakhari. Mansurchak, Birpur, Dandari, Nawkothi, Garhpura, and Chhaurahi The average population density is app. 900 persons per square kms. The economy is mainly agriculture based and the major crops are wheat, maize, chilli, sugarcane etc.
Two big industries mark the skyline of the district i.e. Thermal power station and Petro-Chemicals factory and Oil refinery complex at Barauni. Earlier Barauni Fertilizer was also an important industry which is now non functional. Rajendra Bridge across Ganges at Barauni forms an important link way connecting north and south Bihar, Resting spot for migratory birds in a wetland known as Kanwar tal and the Ghats of Ganga at Simaria possessing religious importance, exists as a potential tourist spots.
