What is the caste system and how did it begin?

What one these showed the changing culture at the beginning of the 20th century? When did the renaissance start and end? How do gladiators dress? What nationality is the last name zivic? How much dark elixir does the barbarian king cost? What is the origin of the name kosciusko? What is the difference between knights and nobles? Who is a cobbler from the 1700s? Which event occurred first in the history of European seagoing exploration? What are some achievements of civilization? What is the definition of civalization? Which religion first gained popularity as part of the Roman Empire in the 4th century? Where does the surname Callan come from? What country was responsible for introducing livestock and cattle ranching in the southwest? When was the toilet paper invented and why? What was the crusades about? What was the most horrible punishment in the medieval times? How is the first crusade similar to the third crusade? What did Romans do with shields? What group of people gave the best attempt to restore the Roman Empire in Western Europe after Rome fell?