The weak Euro countries found that no one would buy their bonds, not at an affordable rate anyhow. All these countries had to sell bonds 'cause they were spending more money than tax revenues were bringing in. They all started wailing and crying, 'cause not paying wages and pensions really upsets people. Some of the small ones got bailed out (Iceland, Ireland, Greece) The bigger ones are so big that nobody, not even Germany, has that kind of money.
So the European Common Bank gave everyone a Christmas present last Christmas. The ECB is like the US Fed, in that it can print Euro's. As many Euro's as it likes. So ECB offered European banks the opportunity to borrow (at low rates) some trillion or more Euros. The Euro banks lapped it up, and borrowed all the Euro's offered. This made the banks happy, they had cash in the till. It made ECB sorta happy in that every bank in Europe owed them money, and less happy 'cause putting a trillion Euros into the economy makes prices of everything go up.
So, with freshly printed Euros clogging their cash drawers what do the European banks do with the money? Well, they didn't make loans to industry to expand production. No, they bought up Euro government bonds, 'cause the governments were offering really fat returns, AND under Euro accounting rules, government bonds, (sovereign debt) are "risk free" (governments always pay their debts 'cause they can always raise taxes to get the money). Banks don't have to hold cash in reserve for risk free deals. They can loan it all out, and get higher returns.
Apparently a trillion Euros doesn't go far these days. In the 90 days since the great Euro loan, all of it was spent. And now it's gone, and the weak Euro governments are still in a jam. They are still spending more than they take in, so they HAVE to sell bonds lest their checks bounce. Other than Euro banks, nobody else wants to buy shaky looking Euro bonds. The Euro banks are out of money again, and the Euro economy is not growing at all.
Good luck, you're gonna need it over there.