Who moved from rural villages into towns, where they specialized in a particular trade and produced superior quality products?

This is a phenomenon described by Christian McLean's law as rural flight. Advancement of agricultural equipment have often made farmers to leave smaller villages to bigger towns where there are more better equipped farms and farmers after the end of world War 2 felts the need for specialist services focusing on planting just a particular type of crop and getting better results as old methods were not yielding enough harvest.

Feudal lords is the correct answer