About Allahabad
Allahabad, officially known as Prayagraj, and also known as Illahabad and Prayag, is a city in the Indian state of Uttar Pradesh. It is the administrative headquarters of Allahabad district—the most populous district in the state and 13th most populous district in India—and the Allahabad division.
The city lies close to Triveni Sangam, "three-river confluence", original name – Prayag, "place of sacrifice or offering" – which lies at the sangam (confluence) of the Ganga, Yamuna and Sarasvati rivers, a propitious place to conduct sacrifices. It plays a central role in Hindu scriptures. Allahabad was originally called Kaushambi (now a separate district) by the Kuru rulers of Hastinapur, who developed it as their capital. Since then, the city has been a political, cultural and administrative centre of the Doab region. In the early 17th century, Allahabad was a provincial capital in the Mughal Empire under the reign of Jahangir.
Source : Wikipedia