The Patiala and East Punjab States Union was an erstwhile separate state in the newly independent the Dominion of India or Union of India. The territory was established after the nation gained independence from the British administration and existed from the year 1948 till 1956. The territory was formed with the merger of eight princely states of India, namely, Nalagarh, Maler Kotla, Kalsia, Faridkot, Kapurthala, Nabha, Jind and Patiala. The Patiala and East Punjab States Union, abbreviated as PEPSU, was established on 15th July 1948. Later in the year 1950, the region officially became a part of India. The capital and main city of the State was at Patiala. The formed Indian state was scattered over an area of 26,208 sq km. the regions of Chail, Dharampur, Kandaghat, Kasauli and Shimla were also incorporated as a part of the Patiala and East Punjab States Union.

History of Patiala and East Punjab States Union
After the Patiala and East Punjab States Union was inaugurated, the then native ruler or Maharaja of the former princely state of Patiala, His Highness Maharajadhiraj Yadavindra Singh, became the Rajpramukh of the state. He remained in office during the period of the short existence of the state. His Highness Jagatjit Singh of Kapurthla, the then Maharaja of the princely state of Kapurthala, was appointed as the Uparajpramukh of the States Union. On 13 January 1949, Gian Singh Rarewala became the first Chief Minister of Patiala and East Punjab States Union. On 23 May 1951, Colonel Raghbir Singh became the next Chief Minister and Brish Bhan served as the Deputy Chief Minister.

The state established a legislative assembly with 60 elected members on 6 January 1952. The Indian National Congress Party won 26 seats and the Akali Dal won 19 seats. Gian Singh Rarewala was elected as the Chief Minister of the state on 22 April 1952. He led a coalition government, known as the United Front, which was formed by the Akali Dal and several other independent parties. On 5 March 1953, President's rule was imposed on Patiala and East Punjab States Union, after the cancellation of his government. In the following mid-term poll, the Indian National Congress party secured a majority and Raghbir Singh was appointed as the Chief Minister on March 8, 1954. After his death, Brish Bhan succeeded him and served as the Chief Minister on 12 January 1955. He remained in office until 1 November 1956, when the state was merged with the Indian state of Punjab.

A portion of the erstwhile Patiala and East Punjab States Union, together with the south eastern part near Jind and the Narnaul enclave, is currently located in Haryana state. It was detached from Punjab on 1st November 1966. There were some other territories wich belonged to the Patiala and East Punjab States Union, particularly Nalagarh and Solan, is presently situated in the Indian state of Himachal Pradesh.

Sub-divisions of Patiala and East Punjab States Union
In the year 1948, the Patiala and East Punjab States Union was initially divided into 8 districts, which are mentioned below-
* Bhatinda district
* Barnala district
* Fatehgarh district
* Kapurthala district
* Kohistan district
* Mohindergarh (Mahendragarh) district
* Patiala district
* Sangrur district

Later in the year 1953, the number of districts was condensed from 8 to 5 districts. Barnala district was included as a part of the district of Sangrur; where as Fatehgarh and Kohistan districts were merged with the district of Patiala. There were 4 Lok Sabha constituencies in the Patiala and East Punjab States Union. Three constituencies among them were single seat constituency, namely Patiala, Sangrur and Mohindergarh. The Lok Sabha constituency of Kapurthala Bhatinda was a double seat constituency.