The city took 265 years to build. It took one afternoon to rename.

By 1720, 江戸 (Edo) was the largest city on earth — more than a million souls crowded onto the mudflats that Tokugawa Ieyasu 徳川家康 (Tokugawa Ieyasu) had chosen in 1590, a former fishing village transformed into a metropolis that dwarfed London and Paris. The great castle at its center was the largest in the world. Every stone of it, every moat and watchtower and tile roof, announced the same truth: the shogun ruled Japan from this city, and this city was his monument.

On the 17th day of the 7th month of 慶応四年 (Keiō yonen) — the traditional Japanese lunisolar calendar date, corresponding to September 3, 1868 in the Western calendar — a fifteen-year-old emperor put his seal to an edict. The 江戸ヲ称シテ東京ト為スノ詔書 (Edo wo shōshite Tōkyō to nasu no shōsho), the imperial proclamation renaming Edo the Eastern Capital, changed nothing physically. The canals were still there. The castle still stood. The streets still ran in the same directions the Tokugawa engineers had laid out two and a half centuries before.

What changed was the claim. Edo had always been the shogun's city — its very existence a declaration that power in Japan flowed from the warrior class, not from the imperial court in Kyoto. Now it was 東京 (Tōkyō), the Emperor's Eastern Capital, a name that pointed eastward and forward, away from the ancient imperial tradition, toward something modern and singular.

The renaming was proposed by Ōkubo Toshimichi 大久保利通 (Ōkubo Toshimichi), one of the key architects of the Meiji Restoration. The Tokugawa family had surrendered Edo Castle in May 1868; the edict came three months later, consolidating in language what had already been accomplished in fact. Emperor Meiji himself did not physically arrive in his new capital until November 1868, traveling from Kyoto in a procession of more than 3,000 people — a journey from the seat of a millennium-old imperial tradition to the bones of a city built by his enemies.

The Tokugawa shogunate had not ended with a great battle. The decisive engagements were smaller, scattered, anticlimactic. It ended instead with paperwork: an edict, a new name, a fifteen-year-old emperor's seal. The city the Tokugawa had built to announce their own permanence became, in a single stroke, the instrument of their erasure.