Hyderabad is the capital and largest city of the southern Indian state of Andhra Pradesh. Occupying 650 square kilometres, along the banks of the Musi River, it has a population of 6.8 million and a metropolitan population of 7.75 million, making it the fourth most populous city and sixth most populous urban agglomeration in India. At an average altitude of 542 metres, much of Hyderabad is situated on hilly terrain around artificial lakes, including Hussain Sagar—predating the city's founding—north of the city centre.Established in 1591 by Muhammad Quli Qutb Shah, Hyderabad remained under the rule of the Qutb Shahi dynasty for nearly a century before the Mughals captured the region. In 1724, Mughal viceroy Asif Jah I declared his sovereignty and created his own dynasty, also known as the Nizams of Hyderabad. The Hyderabad State ultimately became a princely state during British rule, and remained so for 150 years, with the city serving as its capital. The city continued as capital of a new Hyderabad State after joining the Indian Union in 1948 and before attaining its current status as the focal point of Andhra Pradesh in 1956.Hyderabad city would be part of Telangana but it will first serve as the shared capital of Telangana and Andhra Pradesh for the duration of ten years.Relics of Qutb Shahi and Nizam rule remain visible today, with the Charminar—commissioned by Muhammad Quli Qutb Shah himself—coming to symbolise Hyderabad. Golconda fort is also a major landmark of Hyderabad. That legacy is also evident in the city's distinctive cuisine, which includes Hyderabadi biriyani and Hyderabadi haleem. The Qutb Shahis and Nizams established Hyderabad as a cultural hub, attracting men of letters from different parts of the world. Hyderabad emerged as the foremost centre of culture in India with the decline of the Mughal Empire in the mid-19th century, with artists migrating to the city from the rest of the Indian subcontinent. While Hyderabad is losing its cultural pre-eminence, it is today, due to the Telugu film industry, the country's second-largest producer of motion pictures.Hyderabad was historically known as a pearl and diamond trading centre, and it continues to be known as the City of Pearls. Many of the city's traditional bazaars, including Laad Bazaar, Begum Bazaar and Sultan Bazaar, have remained open for centuries. However, industrialisation throughout the 20th century has also attracted major Indian manufacturing, research and financial institutions, including the Bharat Heavy Electricals Limited, National Geophysical Research Institute and the Centre for Cellular and Molecular Biology. Special economic zones dedicated to information technology have encouraged companies from across India and around the world to set up operations and the emergence of pharmaceutical and biotechnology industries in the 1990s led to the title of Genome Valley. With an output of US$74 billion, Hyderabad is the fifth-largest contributor to India's overall gross domestic product.