The Growth of Food Production in the Roman Empire

The development of the three field rotation system, where it became common for peasants to a cultivate two fields at a time, while leaving a corresponding third field fallow each year. This was a better calebrated system of maintaining soil and fertility than had been known in the ancient world. And it made the land much more productive per person than it had been before. So all this, a creation of food surplus, allows for a towns and cities. Many cities had been quite large a dense in the roman era, but had more or less been abandoned and were largely ruined in the dark age. But now with this greater stability and consolidation and the greater food production, a lot of towns