[4] Other historians suggest that the area was named after the Rai Bahadurs of Tarash who founded a marketplace in present-day Raiganj.

Emperor Gopala II (r. 940-960) dug a 174 bigha lake known as Jaysagar, located 1 km west of the Nimgachhi Bazar in Sonakhara Union.

[5] On 27 January 1922, hundreds of people were killed in Salanga when the British colonial authorities indiscriminately opened fire on a rally led by Abdur Rashid Tarkabagish as part of the Swadeshi movement.

[4] During the Bangladesh Liberation War of 1971, the areas of Chandaikona Bazar, Pangashi, Salanga and Dhangara were plundered and its inhabitants were mass killed with many houses set on fire.

It is bounded by Sherpur and Dhunat upazilas (Bogura) on the north, Ullahpara and Kamarkhanda on the south, Tarash on the west and Sirajganj Sadar on the east.

Raiganj had a literacy rate (age 7 and over) of 38.14%, compared to the national average of 51.8%, and a sex ratio of 1003 females per 1000 males.

[9] The 174 bigha 10th-century Jaysagar reservoir is famed across North Bengal and is 1 km west of the Nimgachhi Bazar in Sonakhara Union.

Main crops: Paddy, jute, potato, sugarcane, wheat, pulse, vegetables and fruits Mango, jack-fruit, litchi, banana, papaya, guava, blackberry.