The history of the area that now constitutes Himachal Pradesh dates to the
Indus valley civilisation that flourished between 2250 and 1750 BCE.
 Tribes such as the Koili, Hali, Dagi, Dhaugri, Dasa, Khasa, Kinnar, and
Kirat inhabited the region from the prehistoric era.
Vedic period, several small republics known as Janapada existed which were later conquered by the
Gupta Empire. After a brief period of supremacy by King
Harshavardhana, the region was divided into several local powers headed by chieftains, including some
Rajput principalities. These kingdoms enjoyed a large degree of independence and were invaded by
Delhi Sultanate a number of times.
Mahmud Ghaznavi conquered
Kangra at the beginning of the 10th century.
Sikander Lodi also marched through the lower hills of the state and captured a number of forts and fought many battles.
 Several hill states acknowledged
Mughal suzerainty and paid regular tribute to the Mughals.
Kingdom of Gorkha conquered many kingdoms and came to power in
Nepal in 1768.
 They consolidated their military power and began to expand their territory.
 Gradually, the
Kingdom of Nepal annexed
Shimla. Under the leadership of
Amar Singh Thapa, the Nepali army laid siege to Kangra. They managed to defeat
Katoch, the ruler of Kangra, in 1806 with the help of many provincial chiefs. However, the Nepali army could not capture Kangra fort which came under
Maharaja Ranjeet Singh in 1809. After the defeat, they began to expand towards the south of the state. However, Raja Ram Singh, Raja of Siba State, captured the fort of Siba from the remnants of Lahore Darbar in Samvat 1846,
 during the
First Anglo-Sikh War.
They came into direct conflict with the British along the
tarai belt after which the British expelled them from the provinces of the
 The British gradually emerged as the paramount power in the region.
 In the revolt of 1857, or first
Indian war of independence, arising from a number of grievances against the British,
 the people of the hill states were not as politically active as were those in other parts of the country.
 They and their rulers, with the exception of Bushahr, remained more or less inactive.
 Some, including the rulers of
Bilaspur, Bhagal and Dhami, rendered help to the British government during the revolt.
The British territories came under the British Crown after
Queen Victoria's proclamation of 1858. The states of
Mandi and Bilaspur made good progress in many fields during the British rule.
World War I, virtually all rulers of the hill states remained loyal and contributed to the British war effort, both in the form of men and materials. Among these were the states of
Kangra, Jaswan, Datarpur, Guler,
Nurpur, Chamba, Suket, Mandi, and Bilaspur.
After independence, the Chief Commissioner's Province of Himachal Pradesh. was organized on 15 April 1948 as a result of integration of 28 petty princely states (including feudal princes and zaildars) in the promontories of the western
Himalaya. These were known as the Simla Hills States and four Punjab southern hill states under the Himachal Pradesh (Administration) Order, 1948 under Sections 3 and 4 of the Extra-Provincial Jurisdiction Act, 1947 (later renamed as the Foreign Jurisdiction Act, 1947 vide A.O. of 1950). The State of Bilaspur was merged into Himachal Pradesh on 1 April 1954 by the Himachal Pradesh and Bilaspur (New State) Act, 1954.
Himachal became a part C state on 26 January 1951 with the implementation of the
Constitution of India and the Lieutenant Governor was appointed. The Legislative Assembly was elected in 1952. Himachal Pradesh became a
union territory on 1 November 1956.
 Some areas of Punjab State—namely Simla, Kangra, Kulu and Lahul and Spiti Districts, Nalagarh tehsil of
Ambala District, Lohara, Amb and Una kanungo circles, some area of Santokhgarh kanungo circle and some other specified area of Una tehsil of
Hoshiarpur District, besides some parts of Dhar Kalan Kanungo circle of Pathankot tehsil of
Gurdaspur District—were merged with Himachal Pradesh on 1 November 1966 on enactment by Parliament of Punjab Reorganisation Act, 1966. On 18 December 1970, the State of Himachal Pradesh Act was passed by Parliament, and the new state came into being on 25 January 1971. Himachal became the 18th state of the Indian Union with
Dr. Yashwant Singh Parmar as its first chief minister.