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'' (composed between 400 BCE and 200 CE, but describing an earlier time); however, excavations in the area have revealed no signs of an ancient built environment.  In the early 11th-century, a small fort was built in the southern region of Delhi by the Tomaras.  From the early 13th-century until the mid-19th century, Delhi was the capital of two major empires of North India, first of the Delhi sultanate and then of the Mughal empire.  In 1911, it became the capital of the British Indian Empire.  After independence in 1947, it was the capital of the Dominion of India, and since 1950 of the Republic of India.  For many centuries, Delhi had been a dominant trading and commercial centre in North India, and since the 1990s it has been a notable part of the international corporate and financial network.——