Allahabad, also known as Prayag, is a metropolitan city in the north Indian state of Uttar Pradesh. It is the administrative headquarters of the Allahabad District. As of 2011, Allahabad is the seventh most populous city in the state and the thirty-sixth most populous city in India, with an estimated population of 5.11 million living in the city and 1.21 million in its metropolitan region. In 2011, it was ranked the world's 130th fastest growing city.
The city's original name – Prayaga, or "place of offerings" – comes from its position at the sacred union of the rivers Ganges, Yamuna and Saraswati. It is the second-oldest city in India and plays a central role in the Hindu scriptures. Allahabad was originally founded as Kaushambi (now a separate district) by the Kuru rulers of Hastinapur, who developed it as their capital. Since then, Allahabad has often been the political/cultural/administrative head of the entire Doab area and beyond. Later, the Mughal emperor Akbar renamed Prayag as Allahabad and made it a prominent administrative centre. In 1833 it became the seat of Ceded and Conquered Provinces before the capital was shifted to Agra in 1835. It again became the capital of North-Western Provinces in 1858 when it was also made the capital of India for a day. Eventually, it served as the capital of United Provinces from 1902 to 1920.
Located in the southern part of Uttar Pradesh, the city's metropolitan area is 63.07 km2 (24.35 sq mi). While the city and surroundings are governed by several municipalities, a large portion of Allahabad District is governed by the Allahabad City Council. As a large and growing city, it is home to colleges, research institutions and central and state government establishments. Allahabad has hosted cultural and sporting events, including Kumbh Mela and Indira Marathon. Although Allahabad's economy was built on tourism, its main revenue now comes from real estate and financial services