The US first lady electrified the Democratic National Convention as her husband, Barack Obama, was formally nominated to run for re-election. To cheers from the delegates in Charlotte, North Carolina, Obama said her husband understood that "success isn't about how much money you make. It's about the difference you make in people's lives."

Europe's top banker won approval for a new and potentially unlimited bond-buying programme intended to lower struggling euro-zone countries' borrowing costs and draw a line under the debt crisis. The announcement by the European Central Bank chief led to strong gains on markets worldwide.