PATIALA AND EAST PUNJAB STATES UNION, or PEPSU, was established on 5 May 1948 by the merger of the 8 East Punjab courtly regions of Nabha, Patiala, Jind, Kalsia, Kapurthala, Nalagarh, Faridkot, and, Malerkotia. It was officially opened on 15 July 1948 by Sardar Vallabhbhai Patel, India's Deputy Prime Minister. With Maharaja Yadavinder Singh of Patiala succeeded over as Rajpramukh or ruler on August 20, 1948, the Union government began to operate.

Sardar Patel's approach of bringing the Lordly republics together has its origins in the integrating initiatives devised by the British parliamentary section during World War II. After the Declaration of Independence, though, initiatives evolved on a much stranger turn. The British-envisioned organizational unification created the path for the Government of India to consolidate roughly 600 princely kingdoms into larger and more sustainable activist parties, and PEPSU was among them.

Patiala, Kohistan, Bathinda, Sangrur, Fatehgarh Sahib, Kapurthala, Barnala, and Mohindergarh were the 8 provinces that made up the Union. The first 5 stages were continuous and mostly situated in the Malva region south of the Sutlej, whereas Kapurthala was north of the river, Mohindergarh was southeast of Rajasthan, and Kohistan was northeast of Himachal Pradesh.