Administrative History of Himachal Pradesh

• The Himachal Pradesh was constituted as a Chief Commissioner’s province on 15th April, 1948 after the merger of 30 erstwhile princely hill states. These States were Baghat, Bhajji, Baghal, Bija, Balsen, Bushehar, Chamba, Darkoti, Deloth, Dhadi, Dhami, Ghund, Jubbal, Knaneti, Kyarkoti, Kumarsein, Kunihar, Kuthar, Mandi, Madhan, Mahlog, Mangal, Kot, Keonthal, Ravinigarh, Sangri, Sirmaur, Suket, Tharoach and Theog.
• The bigger states like Chamba and Sirmaur were directly converted into districts with the same names.
• The states of Mandi and Suket were integrated to form Mandi district.
• 26 Shimla Hill States including their tributaries were integrated to form the Mahasu district.
• Thus the Himachal Pradesh was divided into four districts viz. Chamba, Sirmaur, Mandi and Mahasu with an area of 27,169 square kilometres.
• On 1 July 1954, the neighbouring Part C State of Bilaspur was integrated with Himachal Pradesh, thereby adding one more district with an area of 1167 square kilometres.
• On 1 May 1960, the Chini tehsil of Mahasu district was carved out as a separate administrative unit and district Kinnaur was formed raising the total number of districts to six.
• On 1 November 1966, the Punjab hill areas were integrated with Himachal Pradesh constituting the four new districts viz. Kullu, Lahaul & Spiti, Kangra and Shimla. With this addition, Himachal Pradesh comprised of ten districts with an area of 55,673 square kilometres.
• On 1 September 1972, two more districts viz. Hamirpur and Una were created by trifurcation of Kangra district raising the total number of districts to twelve. Mahasu and Solan districts were reorganised as Shimla and Solan districts.