The most famous highway in Japan, the Tôkaidô (literally Eastern Sea Road), began as a unit in the Five Provinces and Seven Circuits (gokashichidô) administrative structure adopted by one of the earliest governments in Japan, during the late Asuka period (538–710) and early Nara period (710–794). Using a Chinese model, the regime deployed geography among other tools to imagine a broader and more comprehensive political scope than had previous sovereigns, claiming authority over not just a lineage or a region but an area approaching what is now known as the Japanese archipelago. That version of the Tôkaidô included the nine provinces of Iga, Ise, Shimo, Owari, Mikawa, Tôtômi, Suruga, Izu, and Kai, with Sagami, Musashi, Awa, Kazusa, Shimôsa, and Hitachi added a few years later.1 This region extends from east to west across the central zone of Japan’s main island of Honshû, connecting what are today the two main urban regions of a densely populated landmass, but which in the seventh and eighth centuries were the two most significant agricultural flatlands: the Kinki plain in the west and the Nobi plain in the east. The unit was not merely a product of the political imaginary, but a well-trodden path through passes, valleys, alluvial flats, and coastal plains.
Tokugawa Ieyasu’s birthplace, Okazaki, was located in Mikawa Province, on the western side of this horizontal strip of territory. Its castle, like most static fortifications in this period, took advantage of the local geography and was strategically situated on a hill, protected to the west by the Yanagi River and to the south by its estuary. Sunpu in Suruga Province, where Ieyasu was raised, was located on the eastern side of the Tôkaidô. Its castle was also protected on two sides, with mountains to the west and Suruga bay to the south. Hamamatsu, which Ieyasu had made his base of operations in 1570, was located roughly in the center of the Tôkaidô territory, forming a kind of triangular topos of Ieyasu’s movements in the first half of his life. Its castle was built in the coastal plain between Lake Hamana and the Tenryû River. This Tôkaidô territory—no longer an administrative unit by the late sixteenth century but still part of the discourse of the region—was also home to many of the major players in late-medieval war and politics: the Oda to the west, the Hôjô to the east, and the recently defeated Takeda—with a domain that had extended from the Tôkaidô into the next defunct administrative territory, the mountainous Tôsandô (literally Eastern Mountain Road)—to the north.
What is striking is the extent to which this territory of the Tôkaidô—and indeed, as the term would come to signify the highway connecting Edo and Kyoto/Osaka rather than the old administrative unit, that roadway as well—demarcated and mapped Ieyasu’s activities. He only ventured out of its confines on two occasions (once to Kyushu in the south and once to Mutsu Province in the north), and never for any significant period of time. Ieyasu and his peers traveled back and forth along this east-west passage, from Okazaki to Hamamatsu, from Sunpu to Kyoto, and from Edo to Osaka, inscribing a history of war, diplomacy, chance, and ritual into the collective memories of its people and locales. Early modern tourists traversing the highway long after Ieyasu’s death could stop in Sunpu or Okazaki, and encounter pacified and in some cases commodified versions of the Tokugawa founder through the genealogy of famous places (meisho).2
This geography is key to understanding the rapid shifts in the political fortunes of Ieyasu and his contemporaries. Nobunaga was assassinated in part because he allowed himself to be isolated in Kyoto, with his major generals scattered in campaigns too far from the capital to protect him. After Hideyoshi picked up the pieces and began forming a new national coalition, Ieyasu was protected from the Toyotomi lord's advances in part because he was firmly ensconced in eastern territories that he knew so well—Mikawa, Tôtômi, and Suruga, the heartland of the Tôkaidô. And once Ieyasu did bow down to Hideyoshi to become a vassal of the new Toyotomi regime, he protected himself by moving his base of operations even further to the east from Hamamatsu, to his old childhood home of Sunpu. This eastward creep reached its logical conclusion in 1590 with Ieyasu’s transfer to the eastern provinces of the Kantô region, a move that would have far-reaching consequences for Ieyasu, for the Toyotomi house, and indeed for Japan. Geography, as John Allen put it, “makes a difference to the exercise of power,” and the overlap between Ieyasu’s personal geography and the map of political and economic flows in the Tokugawa period is no accident.3
1. See Tana’ami Hiroshi, Kodai no kôtsû (Tokyo: Yoshikawa Kôbunkan, 1995).
2. See Jilly Traganou, The Tôkaidô Road: Traveling and Representation in Edo and Meiji Japan (New York: RoutledgeCurzon, 2004), Laura Nenzi, Excursions in Identity: Travel and the Intersection of Place, Gender, and Status in Edo Japan (Honolulu: University of Hawai’i Press, 2008), and Constantine Nomikos Vaporis, Tour of Duty: Samurai, Military Service in Edo, and the Culture of Early Modern Japan (Honolulu: University of Hawai‘i Press, 2008) on the highway in the early modern and modern periods.
3. John Allen, Lost Geographies of Power (Oxford: Wiley-Blackwell, 2003), 1.