How did the crusades and mercantilism affect the feudal system?

Who controlled the holy roman empire in the late renaissance? How did the Romans learn about Greek culture? How did knights and lords try to make their manors self-sufficient? How did medieval age man communicate? Who was the third crusade foght against? What were three forms or writing in which the Romans excelled? Who is Frederick Gates? What does the name Karlin mean? What does it mean when you say someone has met their Waterloo? What happened during the 1600s that dramatically changed the living environment and main food source of the plains Indians? What are the similarities and differences of the attitudes of Christianity and Islam toward merchants and trade from their origins until about 1500? Why is Henry Purcell so important? What is a medieval stable? What are the similarities and differences among the world's earliest civilization? What century is 1960? Did chavalrous knights really exist? How many different calendars are still in use today? What did Walter cronkite mean when he said with each escalation the world comes closer to the brink of cosmic disaster? How many years has it been since 1945? What happened in year 1000?