The European Central Bank (ECB), as the monetary union's central bank, played a critical role in the European debt crisis and acted as a lender of last resort, providing banks with cash flow in exchange for collateral, as well as a buyer of last resort. Mario Draghi, President of the ECB from 2011 to 2019, expressed his commitment to saving the Euro and to European integration in his now famous “whatever it takes” speech in July 2012.  The bank is based in a twin-tower skyscraper in Frankfurt/Main, designed for the ECB, which integrates the city's former historical wholesale market hall. The building officially opened on March 18, 2015.