The Habitable Planet This course will guide viewers through topics including the atmosphere, oceans, and ecosystems, as well as the impact of human activities and population growth on water and food resources, biodiversity, energy use, and global pollution. Each of the 13 programs in the series includes two case studies featuring the work of top scientists in the field.
or safety and for
defense, people in the Middle Ages formed small communities
around a central lord or master. Most people lived on a manor,
which consisted of the castle, the church, the village, and
the surrounding farm land. These manors were isolated, with
occasional visits from peddlers, pilgrims on their way to the
Crusades, or soldiers from other fiefdoms.
In this "feudal" system,
the king awarded land grants or "fiefs" to his most
important nobles, his barons, and his bishops, in return for
their contribution of soldiers for the king's armies. At the
lowest echelon of society were the peasants, also called "serfs"
or "villeins." In exchange for living and working
on his land, known as the "demesne," the lord offered
his peasants protection.
or safety and for
defense, people in the Middle Ages formed small communities
around a central lord or master. Most people lived on a manor,
which consisted of the castle, the church, the village, and
the surrounding farm land. These manors were isolated, with
occasional visits from peddlers, pilgrims on their way to the
Crusades, or soldiers from other fiefdoms.
In this "feudal" system,
the king awarded land grants or "fiefs" to his most
important nobles, his barons, and his bishops, in return for
their contribution of soldiers for the king's armies. At the
lowest echelon of society were the peasants, also called "serfs"
or "villeins." In exchange for living and working
on his land, known as the "demesne," the lord offered
his peasants protection. 
