Europe is famed for its zippy German cars, French high-speed trains and sleek Italian motorboats. But for decades the contraption most often favoured to describe the workings of the European Union was the humble bicycle. Federalists painted the EU as an inherently unstable machine whose only chance to avoid a crash was to keep moving forward. The self-serving analogy justified furious pedalling by those who dreamed of “ever-closer union” lest the whole thing keel over. By the early 2000s the argument that more integration was always better had made its way. What had once been a modest pact between six countries to regulate coal and steel production had morphed into a political union of 25 (later up to 28), with a shared currency, no internal borders and the rights for citizens from Lisbon to Lapland to settle down where they saw fit. Who could tell where a few more decades of such freewheeling towards continental convergence would lead?