Feudalism explained - Video

A very quick explanation of the Feudal System, following this

LINK.

After watching this Video, please respond: 

1. Who was the owner of the land during the Feudal System?

2. Which role played the Great Lords?

3. Explain the relationship: Overlord-Vassal. What was the "Fief"?

4. Why the Feudal system decayed in Europe?