When Ieyasu became shogun in 1603, Edo in turn became the seat of national government and its castle the largest in the world.
Tokugawa Ieyasu is the founder of Edo.
mnli hypothesis: Tokugawa Ieyasu is the founder of Edo. premise: When Ieyasu became shogun in 1603, Edo in turn became the seat of national government and its castle the largest in the world.