Mahabubnagar or Mahboobnagar is the biggest town in the Mahabubnagar District of Andhra Pradesh, India, 139 km from the state capital, Hyderabad. Formerly known as Rukmammapeta and Palamoor, it was named Mahabubnagar on 4 December 1890 in honour of Mir Mahabub Ali Khan Asaf Jah VI, the Nizam of Hyderabad (1869-1911 AD). It has been the capital of the district since 1883 AD. Mahabubnagar is bordered by the Tungabhadra River in the south and surrounded by the Nalgonda, Hyderabad, Kurnool, Raichur and Gulbarga districts. The Golconda diamonds, including the famous Kohinoor diamond allegedly came from Mahabubnagar district.