The Present Himachal Pradesh is, in fact, a post independence creation. Before the advent of freedom, the areas comprising   this Pradesh were divided into numerous principalities or small hill states headed by Rajas or Ranas. The History of each erstwhile state is different.  Although enjoying intemal autonomy, these states were under complete British control.  When India attained freedom, all these states were integrated into a single administrative unit, as a result of which Himachal Pradesh came into being.

Before the formation of Himachal Pradesh, there were about thirty two princely states in the region.  Himachal Pradesh in the beginning was the result of integration of thirty princely state merged to from a ‘C’ state. The four districts of the state were as under:

1. Mahasu	Composing of 26 Princely states (including feudatories,) Bushehar, Keonthal, Baghal, Baghat, Jubbal, Kumarsain, Bhajji, Mehlog, Balsan, Dhami, Ratesh, Ghund, Theog, Madhan, Ravin Dhaddi and Khaneti.
2. Mandi	Mandi and Suket States.
3. Sirmaur	Sirmaur State
4. Chamba	Chamba State

The beautiful mountain state of Himachal Pradesh (HP) was originally formed as a centrally administered territory on April 15, 1948 by the integration of 30 odd Punjab hill provinces. In 1951, it became a Part C State under a Lieutenant Governor, with a Legislative Assembly of 36 members and a Cabinet of three ministers. In 1954, Bilaspur, another Part C State, was merged with HP and the strength of the Assembly was raised to 41 members. In 1956, the States Re-organisation Commission recommended the merger of Himachal Pradesh with Punjab. But the people of HP so stoutly opposed that the proposal was overruled.

Till October 1966, HP consisted of only six hill districts—Mahasu, Mandi, Chamba, Sirmaur, Bilaspur and Kinnaur. In November 1966, it was enlarged with the inclusion of some of the hilly areas of Punjab—Shimla, Kangra, Kullu, Lahaul, Spiti, Nalagarh tehsil of Ambala district, and areas of Hoshiarpur and Gurdaspur districts.

HP was organised into 10 districts and declared a state on January 25, 1971, with Shimla as its capital. In 1972-73, the state was re-organised into 12 districts—Bilaspur, Chamba, Hamirpur, Kangra, Kinnaur, Kulu, Lahaul & Spiti, Mandi, Shimla, Sirmaur, Solan and Una.

After Indian Independence, a Union Territory of Hill states was created. It primarily constituted of hill states around Shimla. On November 1, 1966 Punjab Hill areas were merged into Himachal as part of reorganization of Punjab. Himachal Pradesh became a full fledged state of the Republic of India on January 25, 1971. With the reorganization  of districts in 1972, the state acquired  the present shape and has  got 12 districts  with its  headquarters  at Shimla.