December 12, 1911 – Delhi replaces Calcutta as the capital of India.
Officially the National Capital Territory of Delhi (NCT), it is a city and a union territory of India. It is bordered by Haryana on three sides and by Uttar Pradesh to the east. It is the most expansive city in India—about 1,484 square kilometers (573 sq mi). It has a population of about 25 million, making it the second most populous city after Mumbai and most populous urban agglomeration in India and 3rd largest urban area in the world. Urban expansion in Delhi has caused it to grow beyond the NCT to incorporate towns in neighboring states. At its largest extent, there is a population of about 25 million residents as of 2014. According to data released by Oxford Economics, Delhi NCR urban agglomeration has replaced Mumbai Metropolitan Region urban agglomeration as the economic capital of India. However the comparison of the figures specific to the Metropolis of Delhi and Metropolis of Mumbai was not provided by this institution. These figures however did not match with those revealed by the reserve bank of India, The economic survey of India, The economic survey of Delhi and Maharashtra.
Delhi has been continuously inhabited since the 6th century BCE. Through most of its history, Delhi has served as a capital of various kingdoms and empires. It has been captured, ransacked and rebuilt several times, particularly during the medieval period, and modern Delhi is a cluster of a number of cities spread across the metropolitan region.
In 1911, it was announced that the capital of British held territories in India was to be transferred from Calcutta to Delhi. The name “New Delhi” was given in 1927, and the new capital was inaugurated on February 13, 1931. New Delhi, also known as Lutyens’ Delhi, was officially declared as the capital of the Union of India after the country gained independence on August 15, 1947. During the partition of India, thousands of Hindu and Sikh refugees, mainly from West Punjab fled to Delhi, while many Muslim residents of the city migrated to Pakistan. Migration to Delhi from the rest of India continues (as of 2013), contributing more to the rise of Delhi’s population than the birth rate, which is declining.