Kolkata (English: or , Bengali: [kolkata] (listen); also known as Calcutta , the official name until 2001) is the capital of the Indian state of West Bengal. Located on the eastern bank of the Hooghly River, the city is approximately 80 km (50 mi) west of the border with Bangladesh. It is the primary business, commercial, and financial hub of Eastern India and the main port of communication for North-East India. According to the 2011 Indian census, Kolkata is the seventh-most populous city in India, with a population of 45 lakh (4.5 million) residents within the city limits, and a population of over 1.41 crore (14.1 million) residents in the Kolkata Metropolitan Area. It is the third-most populous metropolitan area in India. In 2021, the Kolkata metropolitan area crossed 1.5 crore (15 million) registered voters. The Port of Kolkata is India's oldest operating port and its sole major riverine port. Kolkata is regarded as the cultural capital of India. Kolkata is the second largest Bengali-speaking city after Dhaka. It has the highest number of nobel laureates among all cities in India.In the late 17th century, the three villages that predated Calcutta were ruled by the Nawab of Bengal under Mughal suzerainty. After the Nawab granted the East India Company a trading licence in 1690, the area was developed by the Company into an increasingly fortified trading post known as Fort William. Nawab Siraj ud-Daulah occupied Calcutta in 1756, and the East India Company retook it the following year. In 1793 the East India Company was strong enough to abolish native rule, and assumed full sovereignty of the region. Under company rule and later under the British Raj, Calcutta served as the capital of British-held territories in India until 1911. In that year, after assessing its geographical location, combined with growing nationalism in Bengal (Calcutta became the centre for the Indian independence movement), the British moved the capital to the relatively more centrally located New Delhi.

Following independence in 1947, Kolkata, which was once the premier centre of Indian commerce, culture, and politics, suffered many decades of political violence and economic stagnation before it rebounded. A demographically diverse global city, the culture of Kolkata features idiosyncrasies that include distinctively close-knit neighbourhoods (paras) and freestyle conversations (adda). Kolkata is home to eastern India's film industry, known as Tollywood, and cultural institutions, such as the Academy of Fine Arts, the Victoria Memorial, the Asiatic Society, the Indian Museum, and the National Library of India. Among scientific institutions, Kolkata hosts the Agri Horticultural Society of India, the Geological Survey of India, the Botanical Survey of India, the Calcutta Mathematical Society, the Indian Science Congress Association, the Zoological Survey of India, the Institution of Engineers, the Anthropological Survey of India and the Indian Public Health Association. Four Nobel laureates and two Nobel Memorial Prize winners are associated with the city. Though home to major cricketing venues and franchises, Kolkata stands out in India for being the country's centre of association football and also having strong culture in other sports less widespread elsewhere.

Delhi (; Hindi pronunciation: [ˈdɪlːiː] Dillī; Punjabi pronunciation: [ˈdɪlːiː] Dillī; Urdu pronunciation: [ˈdɛɦliː] Dêhlī), officially the National Capital Territory (NCT) of Delhi, is a city and a union territory of India containing New Delhi, the capital of India. Straddling the Yamuna river, primarily its western or right bank, Delhi shares borders with the state of Uttar Pradesh in the east and with the state of Haryana in the remaining directions. The NCT covers an area of 1,484 square kilometres (573 sq mi). According to the 2011 census, Delhi's city proper population was over 11 million, while the NCT's population was about 16.8 million. Delhi's urban agglomeration, which includes the satellite cities of Ghaziabad, Faridabad, Gurgaon and Noida in an area known as the National Capital Region (NCR), has an estimated population of over 28 million, making it the largest metropolitan area in India and the second-largest in the world (after Tokyo).The topography of the medieval fort Purana Qila on the banks of the river Yamuna matches the literary description of the citadel Indraprastha in the Sanskrit epic Mahabharata; however, excavations in the area have revealed no signs of an ancient built environment. From the early 13th-century until the mid-19th century, Delhi was the capital of two major empires, the Delhi sultanate and the Mughal Empire, which covered large parts of South Asia. All three UNESCO World Heritage Sites in the city, the Qutub Minar, Humayun's Tomb, and the Red Fort belong to this period. Delhi was the early centre of Sufism and Qawwali music. The names of Nizamuddin Auliya and Amir Khusrau are prominently associated with it. The Khariboli dialect of Delhi was part of a linguistic development that gave rise to the literature of the Urdu language and then of Modern Standard Hindi. Major Urdu poets from Delhi are Mir Taqi Mir, and Mirza Ghalib. Delhi was a major centre of the Indian Rebellion of 1857. In 1911, New Delhi, a southern region within Delhi, became the capital of the British Indian Empire. During the Partition of India in 1947, Delhi was transformed from a Mughal city to a Punjabi one, losing two-thirds of its Muslims residents, in part to the pressure brought to bear by arriving Hindu refugees from western Punjab. After independence in 1947, New Delhi continued as the capital of the Dominion of India, and after 1950 of the Republic of India.

Delhi is home to the second highest number of billionaires and millionaires of any city in India. Delhi ranks fifth among the Indian states and union territories in human development index. Delhi has the second-highest GDP per capita in India (after Goa). Although a union territory, the political administration of the NCT of Delhi today more closely resembles that of a state of India, with its own legislature, high court and an executive council of ministers headed by a Chief Minister. New Delhi is jointly administered by the federal government of India and the local government of Delhi, and serves as the capital of the nation as well as the NCT of Delhi. Delhi is also the centre of the National Capital Region, which is a 'interstate regional planning' area created in 1985.

Delhi hosted the inaugural 1951 Asian Games, 1982 Asian Games, 1983 NAM Summit, 2010 Men's Hockey World Cup, 2010 Commonwealth Games, 2012 BRICS Summit and was one of the major host cities of the 2011 Cricket World Cup.