It was in the leaders' statement after the Pittsburgh summit in September 2009 that the solemn pronouncement came. The old era would receive a ceremonial cremation and a new, stronger one would arise out of its ashes.

“We designated the G20 to be the premier forum for our international economic co-operation,” it said. “After this crisis, critical players need to be at the table and fully vested in our institutions to allow us to co-operate to lay the foundation for strong, sustainable and balanced growth.”

In truth, the critical shift was made almost a year earlier at the Washington summit in 2008. The administration of President George W Bush had been casting around for a credible grouping to convene in support of the world economy. It lit upon the extant but under-used G20. The grouping had in fact been created after the Asian financial crisis in 1997-98, but had largely languished since, its meetings attended by ministers and officials of decreasing seniority as time went on.