For 250 years, Japan maintained an extraordinary peace by forcing the entire warrior class to live in the capital Edo, a city that was essentially a giant consumption machine that produced nothing.
Half its population were samurai pensioners doing busywork, while the daimyo (the ruling elite) were burning money on mandatory mansions and endless processions between their estates. The whole city ran on agricultural surplus extracted from the rest of Japan.
Some surprising facts:
1) The city functioned as a hostage system. The daimyo (regional lords) were required to leave their families permanently in Edo as de facto hostages. Most noblewomen never once visited the lands their husbands governed. Instead, they spent their entire lives in the capital as insurance against rebellion.
2) Half the city were warriors with nothing to fight. At any given time, nearly half of Edo's population were samurai, which were living as state pensioners in a country at total peace. Most did little beyond civil administration and calligraphy lessons, since most work was considered beneath them.
3) It was probably the world's largest city, centuries before Tokyo's modern fame. Edo likely exceeded a million people by 1700. London didn't hit that mark until 1800, New York did not until 1880.
4) It had very high population density, almost entirely in single-storey buildings. Some commoner districts hit twice Manhattan's current density.
5) The poor were taxed at up to 70% of their harvest. The agricultural surplus flowed up through public taxation rather than rent, making the state the direct intermediary between peasants and the elite.