Edo Castle Takes Form

The struggle came to Edo during this period (years and years before Tokugawa took over the hamlet), again in order to protect borders from potential encroaching enemies and to exert control over and deny access to important economic areas. Despite this, Edo was still a backwater.

It is important to note that, rather than protecting against threats originating in the North, this time the fort was used to defend against threats emanating from the South. The Hojo Clan, regents of the Kamakura Shoguns, were still powerful after the fall of the Kamakura Shogunate and were making their influence felt in the Musashi domain – home of the Ogigayatsu-Uesugi clan. Wanting to prevent Hojo expansion, Uesugi Mochitomo ordered his retainer Ota Dokan to build a series of castles to protect his southern flank. One was to become Edojuku (not quite a “castle,” but getting there!).

Ota Dokan, Architect of Edo Castle

Ota Dokan, architect of Edo Castle

Perhaps 200 years even before Tokugawa was born, Dokan used the Edo clan stronghold as the foundation of his new fortress. Where the East Garden of the Imperial Palace is now located, he built three mutually defensive enclosures – strongly defensible right-angle turns where invaders are corralled into carefully sculptured kill-zones called the ko (child), naka (middle), and soto (outer). Immediately behind these last defensive positions is where the honmaru (Central Keep) of Tokugawa Ieyasu’s Edo Castle was later built. These place-names still survive today, as do the massive ramparts (built and rebuilt perhaps several dozen times over the ages).

Construction was launched in February of 1456, and completed just over a year later in April of 1457. In such a short period, the area must have been an incredible beehive of activity. The tremendous amount of earth dug out to carve the initial moat, and the earthen-packing and stonework for the walls, must have been a marvel of human activity (no beasts of burden were used). Again, utilizing the Hira River to establish the eastern moat of the castle, builders over the centuries incorporated topography and geography into a design that stands today. And as a result, the Hira River has essentially disappeared.

Map of old Edo

A map of old Edo


The castle’s high-point overlooking the small harbor of Edo served it well, and so it was continually built-up. Although it was only considered a border fort, it allowed the Uesugi to keep enemies at bay and control the flow of goods into and out of the provinces it straddled. From the highpoint, Mt. Fuji (an ancient Ainu name ascribed to this holy, constantly active volcano) loomed large and dominated the skyline to the West; in the Northeast, an unobstructed view of the bay out as far as the tip of the Boso Peninsula to the Southeast as well as to where Chiba now lies.

Politics, though, often has a way of defeating that which brute force alone cannot topple. Despite bringing stability to the area and rewarding him (and his generations afterwards) for his loyal service to the Uesugi, Dokan ran afoul of his lord, Uesugi Sadamasa. In 1486, Dokan retired to a bath after the evening’s events as a guest of his lord in his massive estate where modern-day Kanagawa is now, a day’s walk away. Here, an assassin attacked and killed him on the orders of a suspicious Sadamasa. And with that, history took another dramatic turn.

The management of Edo Castle slipped immediately out of one family’s possession and into another. For a brief period, the control of the Ota family dominated Edo life but this came to an abrupt end, too. In battle, they were annihilated by an encroaching clan in (at that time, far away) Kokubunji (between Fusa and Tachikawa) in 1564. Such were the times that, in defeat, the entire Ota clan was completely extinguished: all soldiers, retainers, even the children were eliminated. After this, the castle fell into the hands of Hojo Ujihide but, as this additional fiefdom only added to Hojo controlled territory and expanded his reach to the easternmost border of the Kanto plain, the importance of Edo Castle diminished as it ceased to lie, protected by the ocean as it was, on a border of contested control.

History took its next dramatic turn 30 years later when a new master sauntered in with a thousand retainers and looked upon this once impressive overlook: his spoil from a recently won larger conflict. What now caught his gaze was only a run down earthen roof that once was a manor. Inside, muddy water from plants that took root on unkempt thatched roofing collected into puddles on molding tatami. This decay and disarray was mirrored further down the hill and all the way to the waters of the bay. The entire administration of a town, criss-crossed by canals, was in turmoil and shambles. In fact, Field Marshall Tokugawa entered the decaying fortress by crossing two wide planks (discarded deck flooring from a nearby ship), an unimpressive drawbridge into a dirt-floored entrance.

Tokugawa Ieyasu, the man who would become Shogun and whose four generations would rule Japan for 265 years, liked what he saw when he crossed that plank in 1590. Edo would never be the same.