The High Middle Ages was a period of tremendous expansion of population. The estimated population of Europe grew from 35 to 80 million between 1000 and 1347, but the exact causes remain unclear; improved agricultural techniques, the decline of slaveholding, a warmer climate, and the lack of invasion have all been suggested. As much as 90% of the European population remained rural peasants. Many were no longer settled in isolated farms but had gathered into small communities, usually known as manors or villages. These peasants were often subject to noble overlords and owed them rents and other services, in a system known as manorialism. There remained a few free peasants throughout this period and beyond, with more of them in the regions of southern Europe than in the north. The practice of assarting, or bringing new lands into production by offering incentives to the peasants who settled them, also contributed to the expansion of population.
Development of Towns
Castles began to be constructed in the 9th and 10th centuries in response to the disorder of the time, and provided protection from invaders and rival lords. They were initially built of wood, then of stone. Once castles were built, towns built up around them.
A major factor in the development of towns included Viking invasions during the early Middle Ages, which led to villages erecting walls and fortifying their positions. Following this, great medieval walled cities were constructed with homes, shops, and churches contained within the walls. York, England, which prospered during much of the later medieval era, is famed for its medieval walls and bars (gates), and has the most extensive medieval city walls remaining in England today.
The practice of sending children away to act as servants was more common in towns than in the countryside. The inhabitants of towns largely made their livelihoods as merchants or artisans, and this activity was strictly controlled by guilds. The members of these guilds would employ young people—primarily boys—as apprentices, to learn the craft and later take position as guild members themselves. These apprentices made up part of the household, or “family,” as much as the children of the master.
https://courses.lumenlearning.com/boundless-worldhistory/chapter/medieval-life/
