Nagasaki's openness did not begin with the Dutch. Before the age of isolation, the city grew from a little harbor village into a diverse port, thanks to Portuguese traders. Portuguese goods flowed in, including tobacco, bread, textiles and a sponge cake called castella, and they were absorbed into popular Japanese culture. Castella is still Nagasaki's most famous souvenir. Christianity arrived with the traders. Many churches were built, and Christian culture flourished so strongly that Nagasaki earned the nickname Little Rome. Then, in 1587, the powerful daimyo Hideyoshi Toyotomi, afraid that Japan might be conquered, issued an edict expelling missionaries. That tension between welcoming the world and guarding against it runs through the whole story. It helps explain why the later arrangement was so tightly managed, with only certain partners admitted, in a certain place, under certain rules. When you stand on Dejima, you are standing inside the answer Japan eventually settled on.