Why did the Turks attack Constantinople?

Related questions

1. What was Istanbul originally called?
2. Was Constantinople a Roman city?
3. When did the Byzantines lose Italy?
4. How did Constantinople's name change over 1100 years later?
5. What led to the fall of the Byzantine Empire?
6. Who was the greatest sultan of the Ottoman Empire?
7. Was the Byzantine Empire part of the Roman Empire?
8. What countries were part of the Byzantine Empire?
9. What is the Byzantine empire best known for?
10. Why did Byzantine Empire fall?

Tags

1. #muslim
2. #fifteenth
3. #remained
4. #byzantine
5. #europe
6. #defeats
7. #facing
8. #decline
9. #victories
10. #turks
11. #empire
12. #bastion
13. #centuries
14. #ottoman
15. #important
16. #after
17. #century
18. #christian
19. #constantinople