Allahabad, officially known as Prayagraj, also known as Ilahabad, is a metropolis in the Indian state of Uttar Pradesh. It is the administrative headquarters of the Allahabad district—the most populous district in the state and 13th most populous district in India—and the Allahabad division. The city is the judicial capital of Uttar Pradesh with the Allahabad High Court being the highest judicial body in the state. As of 2011, Allahabad is the seventh most populous city in the state, thirteenth in Northern India and thirty-sixth in India, with an estimated population of 1.53 million in the city. In 2011 it was ranked the world's 40th fastest-growing city. Allahabad, in 2016, was also ranked the third most liveable urban agglomeration in the state and sixteenth in the country. Hindi is the most widely spoken language in the city.
Allahabad lies close to Triveni Sangam, the "three-river confluence" of the Ganges, Yamuna and Sarasvati rivers. It plays a central role in Hindu scriptures. The city finds its earliest reference as one of the world's oldest known cities in Hindu mythological texts and has been venerated as the holy city of Prayaga in the ancient Vedas.