Why is there a dragon on the Welsh flag?

Related questions

1. Is it illegal to fly the Australian flag?
2. What does it mean when the flag is half mast at Buckingham Palace?
3. Can you fly three flags on one pole?
4. Is it illegal to fly a flag in the UK?
5. Why is the Scotland flag blue with a white cross?
6. Who was the first black King of Scotland?
7. What is a white dragon?
8. Can I tour Buckingham Palace?
9. What flag has a unicorn on it?
10. Is it against the law to fly the Union Jack?

Tags

1. #welsh
2. #bosworth
3. #dragon
4. #signify
5. #which
6. #battle
7. #carried
8. #cathedral
9. #state
10. #their
11. #henry
12. #supporter
13. #recognised
14. #royal
15. #descent
16. #officially
17. #national
18. #included
19. #tudor
20. #after