Why did Edo grow rapidly during the 17th and 18th centuries?

Edo experienced rapid growth during the 17th and 18th centuries, transforming from a marshy estuary into one of the world's largest cities, primarily due to its status as the seat of the Tokugawa shogunate.1

Several key factors drove this expansion:

• Political Centralization: In 1603, Tokugawa Ieyasu established his government in Edo, effectively controlling the country and drawing the military aristocracy to the city.1
• The Sankin Kōtai System: Inaugurated in 1635, this system required daimyo (feudal lords) to reside in Edo for several months each year and keep their families there permanently. This necessitated a massive infrastructure of merchants and services to support the lords and their retainers, which stimulated the development of a commercial economy and improved communications.2
• Urbanization and Commerce: As castle towns across Japan evolved into commercial hubs, Edo became the primary center for this growth. The city attracted farmers who abandoned the countryside to serve the needs of the burgeoning urban population, leading to a massive influx of residents.3

By the early 18th century, Edo’s population exceeded one million people, solidifying its position as a major global metropolis.13