Hyderabad is the capital of the Indian state of Andhra Pradesh. Located on the banks of the Musi River in the Deccan Plateau, the city is one of the largest in India with an area of 650 square kilometres (250 sq mi) and a population of 6.8 million, while the metropolitan area contains 7.7 million residents, making it the fourth most populous city and the sixth most populous urban agglomeration in the country. In 2008, the nominal gross domestic product (GDP) of Hyderabad was US$ 60 billion—ranking 4th in India and 93rd in the world.
Hyderabad city was established in 1591 CE by Sultan Muhammad Quli Qutb Shah, whose dynasty lasted until 1658 when Mughal emperor Aurangzeb occupied Golconda Sultanate and the city became part of the Mughal empire's Deccan province. In 1724 Asif Jah I, a Mughal viceroy, declared his sovereignty and formed the Asif Jahi Dynasty, also known as the Nizams of Hyderabad. The Nizams ruled the princely state of Hyderabad for more than two centuries, under subsidiary alliance with the British Raj. The city remained the dynasty's capital from 1769 until 1948—when the Nizam signed an Instrument of Accession with the Indian Union following Operation polo. In 1956, the city was merged with Andhra State. Since 1969 Hyderabad is a major center of the Telangana movement, which demands a separate state for the Telengana region of Andhra Pradesh.
Situated on the crossroads of North and South India, the city has been noted for its unique culture. As the capital of the largest and richest Princely state of India, and with the patronage from Nizams, the city established local traditions in drama, art, theater, literature, architecture and cuisine. The city is a regular tourist destination and home to many places of interest, including the UNESCO Asia Pacific Heritage site of Chowmahalla Palace, and other notable landmarks such as the Charminar and Golconda fort. Hyderabad is home to numerous museums, Bazaars, galleries, libraries, sporting events and other cultural institutions, including the Salarjung museum, Laad Bazaar, Hyderabad International Convention Centre (HICC) and Shilpakala Vedika.
Hyderabad was once a global center of the diamond and pearls trade, for which it is known by the nickname as City of Pearls. Since 1990s, Hyderabad has emerged as a hub for the information technology, pharmaceuticals and biotechnology industries, alongside traditional and service industries. Hyderabad International Airport was adjudged the world's fifth best airport. Hyderabad's 13 universities and business schools form a major location for higher education and research among Indian and foreign students. The city is home to the Telugu film industry known as Tollywood. The city was expanded in 2007 and the twin cities of Hyderabad and Secunderabad came under the ambit of a single municipal unit, the Greater Hyderabad Municipal Corporation. As a growing metropolitan city in a developing country, Hyderabad confronts substantial urban pollution, traffic congestion, poverty, overpopulation, and other logistic and socioeconomic problems.