Originally Answered: What are some differences and similarities between the medieval knight and the samurai?
Similarities. Both were a warrior class, who swore loyalty to their feudal lords, and who in turn were rewarded with land and money by those they served. Both enjoyed special privileges in their societies, and place high value on ancestry. At the same time, it was possible for people to "break into" the Knightly/Samurai class for much of both Europe and Japan's feudal eras. Both started out as primarily cavalrymen, though the Samurai increasingly moved towards fighting on foot. Both societies developed elaborate codes of conduct, which was rarely achieved by either group, at least not during turbulent times of war.
Some differences. Knights considered acceptable to surrender to a foe who had defeated them, and in fact this was a source of income for many knights. A captured nobleman or knight could normally expect to be freed upon payment of a ransom. The Samurai developed a code of "death before surrender", which was one of the reasons for the idea of spoke holding such an important place in their history.
Knights spurned the use of missile weapons, while the Samurai considered archery a specifically Samurai weapon. While religion played a significant part in Japanese and Samurai history, it didn't hold the importance religion did in Europe at the time. In fact, there were many Buddhist monastaries filled with warrior monks who were technically not samurai, but certainly as well trained and equipped as that class. While in Europe kingdoms coalesced out of the tribes that controlled areas of the continant, in Japan the move was for the unification of Japan under the leadership of a single ruler. This played into opportunities for samurai to advance in society. Also, while both knights and samurai idealized the idea of a socially graceful, literate, and witty knight/samurai, that was the exception rather than the norm. But literacy was more probable in the samurai than his European counterpart of the time.
Just a few points anyways.