The Group of Twenty (G20) Finance Ministers and Central Bank Governors began meeting in 1999, at the suggestion of the G7 finance ministers in response to the global financial crisis of 1997-99. Since then, there has been a finance ministerial meeting every fall.
In October 2008, in the aftermath of the financial crisis that began in the United States in September, President George W. Bush announced that he would host a meeting of the leaders of the G20 countries - creating the first ever G20 summit - in Washington DC on November, 2008, to coordinate the global response. At that meeting, the leaders agreed to meet again.
Thus British prime minister Gordon Brown agreed to host the second G20 summit in London on April, 2009.
This was followed by the third G20 summit hosted by U.S. president Barack Obama in Pittsburgh on September, 2009 where the leaders agreed to hold the G20 summit every year as a premier economic forum.
The fourth G20 summit will take place in Canada on June, 2010 and the fifth G20 summit will take place in Korea on November, 2010. The G20 will have a larger role in the global governance system.