they all rode horses
The strongest civilizing force in Europe during the early Middle Ages was the Church.
Vikings raided all along the coasts, and up the major rivers, of Europe in the Early Middle Ages.
During the early middle ages, 500 - 1000AD, Europe was a frontier land as it was sparsely populated and undeveloped. ;P
clergy
William the Conqueror.
romans
Manorialism.
Manorialism.
Paris
William the Conquerer
Charlemagne
Steam power