History of Rohtas District is quite interesting. In pre-historic days, the plateau region of the district has been the abode of aboriginals whose chief representatives now are the Bhar and the Oraon tribe. According to some legends, the Kharwar tribe was the original settlers in the hilly tracts near Rohtas. Oraon tribe also claims that they ruled over the area between Rohtas and Patna. The local legend also connects king Sahasrabahu with Sasaram, the headquarters of Rohtas District. It is believed that Sahasrabahu had terrible fight with Saint Parsurama, because of which Sahasrabahu was killed. The term Sasaram is supposed to have been derived from Sahasrabahu and Parsuram. Another historical legend connects Rohtas hill to Rohitaswa,son of Harishchandra, a famous king who was known for his piety and truthfulness.

Further, history of Rohtas District states that this district formed a part of Magadh Empire since 6th century BC to 5th century AD. The minor rock edict of Ashoka, Mauryan Emperor at Chandan Sahid near Sasaram confirmed the Mauryan conquests of this district. In 7th century AD, this district came under the control of Harsha rulers of Kannauj. In 1529 Babur invaded Bihar. When Babur died, Sher Shah Suri took over the region. In 1537 Humayun seized his fortresses at Chunar and Rohtas. Humayun proceeded to Bengal and while on his return journey to Delhi Sher Shah defeated him at Chausa. This victory secured for Sher Shah the imperial throne of Delhi.

The next significant historical event, which shook Rohtas District, was the reign of Raja Chait Singh of Varanasi, his kingdom included large part of Shahabad and his control extended up to Buxar. At Chunar and Ghazipur, the English troops suffered defeat and the very foundation of the English power in India was shaken. But, Chait Singh lost eventually. Rohtas District had a very uneventful history till 1857 when Kunwar Singh revolted against the British Empire in line with the Mutineers of 1857. Most of the heroic details of Kunwar Singh are concerned with Bhojpur District. However, the mutiny had its impact and produced similar uprising and incidents throughout the region. The hilly tracts of the district offered natural escape to the fugitives of the Mutiny. During Independence movement the district had a substantiate contribution in the freedom movement of India. After Independence, Rohtas remained a part of Shahabad District but in 1972 Rohtas became a separate district.