“Millions of people are on the move,” you open your article on migration in Europe, “but does it matter?” (“Europe’s Huddles Masses,” January 20, 2007). Of course it does, but not because people are on the move. They have always been. As witnessed by so many family names across the subcontinent, millions of people who now believe they are English, German, or French have come from lands further east, and would have been Italian, Polish, or Greek if they stayed put. And this is only recent history, of course. What matters is that borders are much more important now than they have ever been in European history. And so are passports, soon to be armed with biometric profiles. They impede people on the move. More important, they make them visible and countable. As well as punishable and banishable. To understand migration, one needs to begin with its history, and especially its history before the erection of barriers to the free movement of people.