Why was Game of Thrones wall built?

Related questions

1. What's so special about Valyrian steel?
2. Which Dragon is the strongest in Game of Thrones?
3. Why did White Walkers take babies?
4. Why must a stark always be in Winterfell?
5. How is Jon Snow real father?
6. How old is the hound in Game of Thrones?
7. Why is Beric Dondarrion sword on fire?
8. What does Nissa Nissa mean?
9. Who is the leader of the White Walkers?
10. Did Arya's dance teacher died?

Tags

1. #house
2. #brandon
3. #thought
4. #stark
5. #entire
6. #current
7. #generation
8. #first
9. #builder
10. #founder
11. #believed
12. #years
13. #events
14. #thrones
15. #night
16. #built
17. #lasted
18. #during
19. #around
20. #winter
21. #which
22. #before