Watch this," says Karl Otto Pohl. "It just came in from London." In a small conference room overlooking the glittering Frankfurt skyline, Europe's most influential banker settles into a leather chair.

At its birth in 1948, the West German Deutsche mark scarcely seemed to be a currency that could produce a miracle. Most of the country’s war-wrecked industry still lay in ruins; the economy was torn ...

Peter Keup can still remember how it felt to hold deutsche marks in his hand. “It was special to even touch this money,” he recalls. “It felt solid. The East German mark was thinner, flimsier.” As a ...