Here are the answers to the rewind-remind-quiz questions:
1. Monks and missionaries spread Christianity to northern Europe.
2. Charlemagne's Frankish Empire was similar to the Roman Empire in size, as it encompassed modern France, Germany, Italy and Spain. Charlemagne was also crowned Roman Emperor.
3. Feudalism and the manorial system developed as an economic and military response to invasions. Knights were given fiefs of land to farm in exchange for military service to lords.
4. Samurai were the warriors who served daimyo lords in medieval Japan, similar to how knights served noble lords in Europe.