Delhi, officially the National Capital Territory of Delhi (NCT), is the capital of India as well as the country's largest and 2nd most populous metropolis. With 16.7 million residents as of the 2011 census, Delhi is also the 8th most populous metropolis in the world. The region has been given special status of National Capital Region (NCR) under the Indian constitution's 69th amendment act of 1991. There are nearly 22.2 million residents in the greater NCR urban area, which includes the neighboring cities of Ghaziabad, Noida, Greater Noida, Gurgaon, Sonepat and Faridabad along with other smaller nearby towns.

Delhi is known to have been continuously inhabited since 6th century BC. Through most period of its history, Delhi has served as a capital of kingdoms and empires. It has been invaded, ransacked and rebuilt several times, particularly during the Medieval era, and therefore today's city of Delhi is a cluster of many capital cities scattered across the city's dimensions. Delhi is also widely believed to have been the site of Indraprastha (the legendary capital of the Pandavas during the times of the Mahabharata). Delhi re-emerged as a major political, cultural and commercial city along the trade routes between northwest India and the Gangetic plain after the rise of the Delhi sultanates. It houses many ancient and medieval monuments, archaeological sites and remains.