[5] The terrain was headquarters of the ancient Ita Kingdom founded by Raja Bhanu Narayan and its capital was in the villages of Bhumiura and Eolatoli.. Copper plates have been found from 930 AD in Paschimbagh, Tengubazar Mandir, Rajnagar.

In the mid-14th century, Shah Ruknuddin settled and propagated Islam in Kadamhata, Ita Pargana.

During the Bangladesh Liberation War, the Panchgaon Factory in Rajnagar Upazila produced cannons under the command of M. A. G. Osmani.

A famous historical cannon, nicknamed Jahankosa, built by Janardan Karmakar remains in display in Dhaka.

Munshibazar is one of the most important commercial unions in this Upazila due to the large number of goods and services.

Rajnagar had a literacy rate (age 7 and over) of 48.62%, compared to the national average of 51.8%, and a sex ratio of 1056 females per 1000 males.