Michael Portillo presents a series revisiting the great moments of history to discover that they often conceal other events of equal but forgotten importance. One of Michael Portillo's earliest political memories is the 1975 vote on whether or not Britain should stay in the Common Market, the early name for what is now the European Union. It felt like a uniquely 20th-century subject. But in this programme, Michael travels to King's Lynn to find out why this town near the Norfolk coast was such an important part of a forgotten Northern European free-trading area that stretched down as far as Cologne in Germany and included most of the Baltic coastline. The Hanseatic League was centred in the German town of Lubbeck but English wool made it an important part of a system that allowed Hansas, or groups of tradesmen, to establish a network of trading centres running alongside the nation states of the time. The League had money enough to raise an army, had a substantial fleet and was important for a number of sovereigns, not least Edward IV of England, when they were in need of a loan. So what were the ambitions of the hugely wealthy tradesmen running the league? And have we forgotten to remember that as well as a story of nation states, European history has long been a story of free trade, ultimately crushed by Queen Elizabeth I in England's case. She wanted to control the wool export monopoly and the considerable wealth that came from it and so had the English Hanseatic centre, by then in London and known as the Steelyards, closed down.