On November 3, 1946, Japan's government promulgated a new constitution, written under the Allied occupation that followed the Second World War, which moved the source of sovereign power from the emperor to the people and set the shape of the state for the decades to come.
The document was drafted quickly with strong input from the occupation staff led by General MacArthur. Its most famous clause, Article 9, renounced war and the keeping of armed forces for that purpose.
The old order fell. The new text held. The vote came in May.
The constitution kept the emperor as a symbol without power, gave women the vote, and built a parliament with real authority, and when it took effect in May 1947 it bound a defeated nation into a system that has been revised not once since, a record that makes the document one of the most stable charters in the world.
Japan has argued for decades over what Article 9 allows, yet the frame set on this date still governs. The peace clause remains the part foreigners quote and Japanese courts test, and the date is now a national holiday for the document itself.
The charter was written in a few weeks under pressure from the occupation, yet it has stood without change longer than most constitutions drafted in calm. Its hold on public life is a fact that surprises visitors who expect more turnover in a fast-moving country.