Edo consequently rapidly grew from what had been a small, virtually unknown fishing village in 1457 to a metropolis with an estimated population of 1,000,000 by 1721, the largest city in the world at the time.
Edo quickly went from being a small, unknown fishing village in 1457, to a metropolis by 1721.  Edo had a population around 1 million and was the largest city in the world at the time.