Shahabad district or Arrah district, headquartered at Arrah was a Bhojpuri speaking district in western Bihar, India, making the western border of Bihar with Uttar Pradesh. In 1972, the district was split into two districts: Bhojpur and Rohtas. Kaimur District was carved out from Rohtas in 1991 and Buxar District from Bhojpur in 1992.