Kalsia was a small Sikh state with its capital at Chhachhrauli in what is now Yamunanagar district of Haryana, founded by Gurbaksh Singh of the Karorasinghia connection in the eighteenth century.
Nalagarh, also called Hindur, was a Rajput hill state at the edge of the Shivaliks in what is now Solan district of Himachal Pradesh.
Both were among the eight states merged into PEPSU in 1948, alongside Patiala, Nabha, Jind, Faridkot, Kapurthala and Malerkotla.
PEPSU was itself merged into Punjab in 1956, and in 1966 the reorganisation distributed the former state territories between Punjab, Haryana and Himachal.
The result is that the eight states which were one union in 1948 are now split across three states, Punjab, Haryana and Himachal Pradesh, and their records are correspondingly scattered.
The smaller ones have no published history at all.
Kalsia's rulers were Sidhu Jats and the state's territory lay in scattered parcels across Ambala district and into the hills, which was typical of the Cis-Sutlej states.
Nalagarh's fort at the town, and Ramgarh fort nearby, survive. Nalagarh is now in Solan district of Himachal Pradesh, on the road from Chandigarh into the hills.
PEPSU lasted eight years. Its capital was Patiala and its High Court sat there, and its dissolution in 1956 moved the whole apparatus into Punjab. The states' own records went with it and have never been catalogued.