Allahabad , also known as Prayag and Ilahabad, is a city in the Indian state of Uttar Pradesh and the administrative headquarters of Allahabad District, the most-populous district in the state. As of 2011, Allahabad is the in the state, fifteenth in the Northern India and thirty-sixth in India, with an estimated population of 1.11 million in the city and 1.21 million in its metropolitan region. In 2011 it was ranked the world's 130th fastest-growing city. Allahabad, in 2013, was ranked the third most livable city in the state (after Noida and Lucknow) and twenty-ninth in the country.