Conservative leader David Cameron, who favours a new special relationship with India, took charge as Britain's youngest Prime Minister in nearly 200 years. He heads a coalition with the support of centrist Liberal Democrats, and vows to put aside party differences and provide a strong and decisive government.43-year-old Cameron, who ended the Labour's 13-year reign, made Liberal Democrats leader Nick Clegg Deputy Prime Minister.Cameron said at a joint press conference with Clegg in London today that the coalition is a five-year arrangement and decisions will be taken in the long term interest of the country.Earlier in the day, Cameron named part of his Cabinet, giving four more posts to Lib Dems, who came third in the May 6 general election which threw up a hung Parliament.Conservatives were the single largest party with 306 seats in the 650-member House of Commons, while Labour bagged 258 and Lib Dems 57.William Hague, a veteran Tory leader, will be the Foreign Secretary while Goerge Osborne will be the new Chancellor of Exchequer. 38-year-old Osborne becomes the youngest Chancellor of the Exchequer in 125 years.Cameron, who heads the first coalition government in 70 years, gave his maiden speech after arriving at the No. 10, Downing Street lanked by his wife Samantha.Cameron, the youngest Prime Minister since 1812 when Lord Liverpool ran the government at the age of 42, identified the challenges before his government as a huge deficit, deep social problems and political system in need of reform.Cameron, who visited India after taking over as the Conservative chief in 2006, has pledged to support its bid for a permanent seat in the United Nations Security Council.His party's manifesto says that the Conservatives will work to establish a new special relationship with India, the world's largest democracy.Prime Minister Manmohan Singh congratulated Cameron on his appointment as the new British Prime Minister and invited him to make an early visit to India. Dr. Singh extended his warm wishes and hoped that the two countries will further strengthen the bonds of friendship.A Downing Street spokesman said after their 10-minute telephonic conversationthat both the reinforced the strong bilateral relationship between India and the United Kingdom and looked forward to strengthening it further.