Under the British Rule, Darbhanga was a part of Sarkar Tirhut up to 1875, when it was constituted into a separate district. The subdivisions had been created earlier – Darbhanga Sadar in 1845, Madhubani in 1866 and Samastipur (then known as Tajpur) in 1867. It was the part of Patna division till 1908, when the Tirhut division was created with its headquarters at Muzaffarpur. As a result of reorganization of districts in the State which took effect in the year 1972, Madhubani and Samastipur subdivision were upgraded as independent districts and then the trimmed Darbhanga district has two subdivisions, viz, Darbhanga Sadar and Benipur consisting of 12 Development Blocks in all. Biraul Subdivision was created in 1992 and six more Development Blocks were created namely Hanuman Nagar, Tardih, Gaura Bauram, Kiratpur, Kusheshwar Asthan East and Alinagar in later stage.
The district is bounded on the north by Madhubani district, on the south by the district of Samastipur, on the east by Saharsa district and on the west by the district of Muzaffarpur and Sitamarhi.

The district takes its name from its only town Darbhanga the District headquarters, which is said to have been founded by one Darbhangi Khan, about whom practically nothing is known. It is also held that the name Darbhanga has been derived from Dwar Banga or Dari – Banga, meaning the ‘door of Bengal’. This derivation does not appear to be very correct as division between Bengal and Bihar has always been further to the east. However, the linguistic and cultural affinity with Bengal may be said to commence from here.
Darbhanga town attained the status of a city (Population 1 lakh and above) in 1961. Darbhanga is the seat of the maharaja of Darbhanga. Laheriasarai which is the seat of district and divisional administration is a part of the Darbhanga town. The Raj area is a well developed and beautifully laid-out complex of palaces, temples, offices, parks, garden and ponds. There are a number of palaces built by the successive Maharajas, important among them being Nargauna Palace, Rambagh Palace, Anandbagh bhawan and Bela Palace. A number of buildings are in the use of the Kameshwar Singh Darbhanga Sanskrit University, Darbhanga and Lalit Narayan Mithila University, Darbhanga. The old Raj Library has been taken over by L. N. Mithilia University. Perhaps Darbhanga is the only city in India, which has two universities in a campus. The Maharajas of Darbhanga have traditionally been very great patrons of art and literature and through their munificence have always provided encouragement to the scholars of Maithili and Sanskrit. Mahesh Thakur who founded the Raj was a renowned scholar of Sanskrit. The estate was conferred upon him by Emperor Akbar who was very much impressed by Raghunandan Jha, a scholar and disciple of Mahesh Thakur.

            The district is noted for its trade in Fish, Mango and Makhana. Among its educational institutions are Chandradhari Mithila College, Chandradhari Mithila Science College, Darbhanga Medical College, Women Institute of Technology and Darbhanga Engineering College and Various other institutions.
There are two Urban Local Bodies – The Municipal corporation Darbhanga and the Benipur Municipal Council. The Benipur Municipal Council has been divided in 29 wards. The Population of Benipur Municupal Council is 75317 as per census 2011.

            Darbhanga is a municipal corporation town. Presently headquarter of Darbhanga district as well as Darbhanga Division. Darbhanga is the 5th largest city of Bihar. It is one of the most important districts and big cities of North Bihar. Darbhanga is also known as Heart of the Mithilanchal. According to census 2011, the total population of the District is 3937385. The Male population is 2059949 and Female population is 1877436. The Population of Darbhanga Town is 371356. Darbhanga district is having a total geographical area of 2279 Sq. Km. It is situated between longitude 85 degree 45 minute East and 25 degree 53 minute North.