When Japan’s civil wars ended in 1600, some 260 daimyō still ruled their own land and kept their own armies. From 1635 the Tokugawa shogunate bound every one of them to Edo: a year in the capital, a year at home, forever — wife and heir left behind as permanent hostages. The 228 domains with a known castle are mapped below, each sized by its rice income and tied to Edo by the road it marched twice a year.
228
Domains mapped
1.02M koku
Largest domain
44%
Costliest year on record
Hover or tap any domain — dot size is its rice income (石高), the arc its road to Edo. 228 of 270 plotted.1,000,000 koku100,00010,000
Chōshū Domain
萩藩 · 毛利
Rice income
369,000
koku · #9 of 270
Distance to Edo
~775 km
heading east
March on foot
~19 days
est. at 40 km/day
Seat
萩城
castle town
≈ 19 days on foot each way · 775 km to Edo Castle — the round trip Chōshū’s lord made every other year, his heir kept in the capital as a hostage.
Punished for backing the losing side at Sekigahara (1600), the Mōri were cut from roughly 1.2 million koku to 369,000. They grew their real harvest to nearly twice the figure they declared — the same number the shogunate used to tax and rank them. In 1868, Chōshū led the rebellion that ended the whole system.
Cost: Declared 369,000 koku; real yield close to 700,000 — nearly double.
The Economic Studies Quarterly (1987); Vaporis, Tour of Duty (2008).
Distance and march time are straight-line estimates at the documented pace of about 40 kilometres (10 ri) a day; the famous domains carry their real, recorded figures. Hover or tap any domain to see the length of its leash.
Tosa, 1688
44%
of the domain budget went to the march and the Edo mansion
Kaga's procession
~3,000
marchers — the rules allowed about 400
Chōshū's ledger
369k → 700k
declared koku vs. real yield
Rank, military duty, and the cost of attendance were all levied on a lord’s 表高 (omote-daka) — his declared rice income. So domains reported as little as they could and developed their land in secret. The Mōri of Chōshū declared 369,000 koku while farming close to twice that.
How the system worked
The device was 参勤交代 (sankin-kōtai), “alternate attendance.” A great lord travelled to Edo with a small army of retainers and kept a second household standing in the capital year-round. The permanent Edo residence, not the march itself, was usually the larger expense — and a lord bankrupted on display had no spare silver to raise a rebellion.
It held for more than 250 years, one of the longest stretches of internal peace in the early-modern world; Edo grew into perhaps the largest city on earth. The system finally broke in 1868, when several of the great western domains — Chōshū and Satsuma among them, grown richer than their ledgers admitted — led the rebellion that ended the shogunate. Edo dropped its name and became 東京, Tōkyō.
How the data works
Each domain’s rice income is its 表高 (official assessed yield) around 1866, from the Shiryōbeya han register, cross-checked against nippon.com and the CODH Han ID dataset. Castle coordinates come from Wikidata; the distance to Edo is a straight line to Edo Castle, and the march estimate divides it by the documented pace of ~40 km/day, so it is an approximation, not a route. The Edo order held roughly 260 大名 at any one time; this set covers the 270 domains with a recorded koku figure, of which 228 have a mapped castle and appear above — the rest are small 陣屋 domains without one.
Source & method
Domain koku: Shiryōbeya, “江戸時代の藩一覧” (Keiō 2 / 1866 omote-daka); nippon.com; CODH Han ID dataset. Coordinates: Wikidata. Processions, march durations and the Tosa budget: Constantine Vaporis, Tour of Duty (U. Hawai’i Press, 2008). Chōshū omote-daka vs. real yield: The Economic Studies Quarterly (1987).
The daimyō are gone, but their castles, their roads, and the words for the long walk to the capital are still the Japanese you’d use to cross the country today.
You just read a map of feudal Japan — and the kanji on it are closer than they look:
城castle道road大名lord参勤交代alternate attendance
JIVX turns a fascination like this into real Japanese: short daily sessions of whole sentences, graded the way a teacher would — not flashcards. Free to start, at your own level.