IndiGo was set up in early 2006 by Rahul Bhatia of InterGlobe Enterprises and Rakesh S Gangwal, a United States-based NRI. InterGlobe holds 51.12% stake in IndiGo and 48% is held by Gangwal Virginia-based company Caelum Investments.IndiGo placed a firm order for 100 Airbus A320-200 aircraft in June 2005 with plans to commence operations in mid-2006.IndiGo took delivery of its first Airbus A320-200 aircraft on 28 July 2006, nearly one year after placing the order, and commenced operations on 4 August 2006 with a service from New Delhi to Imphal via Guwahati. By the end of 2006, the airline had six aircraft. Nine more aircraft were acquired in 2007 taking the total to 15. By December 2010, IndiGo replaced the state run flag carrier Air India as the top third airline in India. It already had 17.3% of the market share, behind Kingfisher Airlines and Jet Airways.By early 2012, IndiGo had taken the delivery of its 50th aircraft in less than six years. IndiGo is known to have placed the largest order in commercial aviation history during 2011 at that time, when Airbus won the US$15 billion deal for 180 aircraft. This deal pushed up the percentage of Airbus aircraft in India to 73%.