Passage: The foundation stone of New Delhi was laid by King George V and Queen Mary at the site of Delhi Durbar of 1911 at Kingsway Camp on 15 December 1911, during their imperial visit. Large parts of New Delhi were planned by Edwin Lutyens, who first visited Delhi in 1912, and Herbert Baker, both leading 20th-century British architects. The contract was given to Sobha Singh. The original plan called for its construction in Tughlaqabad, inside the Tughlaqabad fort, but this was given up because of the Delhi-Calcutta trunk line that passed through the fort. Construction really began after World War I and was completed by 1931. The city that was later dubbed "Lutyens' Delhi" was inaugurated in ceremonies beginning on 10 February 1931 by Lord Irwin, the Viceroy. Lutyens designed the central administrative area of the city as a testament to Britain's imperial aspirations.Soon Lutyens started considering other places. Indeed, the Delhi Town Planning Committee, set up to plan the new imperial capital, with George Swinton as chairman, and John A. Brodie and Lutyens as members, submitted reports for both North and South sites. However, it was rejected by the Viceroy when the cost of acquiring the necessary properties was found to be too high. The central axis of New Delhi, which today faces east at India Gate, was previously meant to be a north-south axis linking the Viceroy's House at one end with Paharganj at the other.  Eventually, owing to space constraints and the presence of a large number of heritage sites in the Northside, the committee settled on the South site. A site atop the Raisina Hill, formerly Raisina Village, a Meo village, was chosen for the Rashtrapati Bhawan, then known as the Viceroy's House. The reason for this choice was that the hill lay directly opposite the Dinapanah citadel, which was also considered the site of Indraprastha, the ancient region of Delhi. Subsequently, the foundation stone was shifted from the site of Delhi Durbar of 1911–1912, where the Coronation Pillar stood, and embedded in the...

Question: When was construction finished?
1931