An original regency (formed on 7 November 1956) of the province, it had an area of 9,703 km2 as at early 2008, prior to the separation out of its southern and its north-western districts respectively to create the new South Labuhanbatu and North Labuhanbatu Regencies on 21 July 2008 (in accordance with Laws Nos.

[1] The Panai Estuary, which consists of the Bilah River and Barumun River are located in this regency, and it was the seat of the ancient Buddhist trading kingdom of Pannai, ca.

11th to 14th centuries, connected to the Bahal temple in North Padang Lawas Regency.

Following the separation off of thirteen districts (kecamatan) to form the new South Labuhanbatu and North Labuhanbatu Regencies on 21 July 2008 (in accordance with the enabling Laws enacted on 24 June 2008), the reduced regency is now divided administratively into nine districts, tabulated below with their areas and their populations at the 2010 Census[2] and the 2020 Census,[3] together with the official estimates as at mid 2023.

[1] The table also includes the locations of the district administrative centres, the number of administrative villages in each district (totaling 75 rural desa and 23 urban kelurahan - the latter chiefly in the town of Rantau Prapat), and its post code.