This week marks a changing of the guard at the European Central Bank, one of the world’s most important financial institutions. The bank, under the stewardship of outgoing president Mario Draghi, was instrumental in averting a collapse of the Euro earlier in the decade, as the BBC’s Andrew Walker recounts. Now, with former IMF Chairman Christine Lagarde on her way in, veteran bond buyer Mohamed El-Erian says there will still be an uphill battle to keep the currency stable. One issue in particular, as Jana Randow, economy editor at Bloomberg in Frankfurt, explains, is keeping German savers from revolting against continued low interest rates. (Picture: Christine Lagarde speaks with Mario Draghi in Luxembourg on June 18, 2015. Picture credit: THIERRY MONASSE/AFP/Getty Images)