Billionaire Square: In the most exclusive address in London, only three of 30 owners are British. Meet the new exotic super-rich neighbours (and find out how they afford to live in houses worth up to £60million)

Behind the opulent facades of Belgrave Square, a quiet social revolution has been taking place: most of the square’s grand mansions have now been bought by foreign multi-millionaires and billionaires. The the international super-rich have been discreetly acquiring the capital’s trophy assets – making this, in the process, the richest residential square in the country.