View the following video on 15th century Mariners

http://www.youtube.com/watch?v=NjEGncridoQ&safety_mode=true&persist_safety_mode=1&safe=active

Why did China have Zheng He sail the treasure fleets?

Why did his trips end?

Why did Portugal become involved in the search for spices?

What role did Henry the Navigator play in Navigation?

What was Vasco Da Gama looking for when he reached India?

What was the Line of Demarcation? Who was responsible for this and who were the recipient?

What myths wre dispelled about Columbus?