A thousand years ago, most visitors to Japan would have arrived by ship at Hakata Bay, the one and only authorized gateway to Japan. Over the ages, Hakata was a staging ground for Japanese troops on their way to Korea and ground zero for foreign invasions of Japan. Through the port passed a rich variety of diplomats, immigrants, raiders, and traders, both Japanese and foreign. "Gateway to Japan" spotlights four categories of cross-cultural interaction - war, diplomacy, piracy, and trade - over a period of eight hundred years to gain insight into several larger questions about Japan and its place in the world: How and why did Hakata come to serve as the country's "front door"? How did geography influence the development of state and society in the Japanese archipelago? Has Japan been historically open or closed to outside influence? Why are Japanese so profoundly ambivalent about other places and people? Individual chapters focus on Chinese expansionism and its consequences for Japan and East Asia as a whole; the subtle (and not-so-subtle) contradictions and obfuscations of the diplomatic process as seen in Japanese treatment of Korean envoys visiting Kyushu; random but sometimes devastating attacks on Kyushu by Korean (and sometimes Japanese) pirates; and foreign commerce in and around Hakata, which turns out to be neither fully "foreign" nor fully "commerce" in the modern sense of the word. The conclusion briefly traces the story forward into medieval and early modern times.