Why does the Queen have two birthdays?

Related questions

1. Who is the tallest leader in the world?
2. Is Facebook blocked in Russia?
3. What languages can the royal family speak?
4. Who was the youngest queen of England?
5. Who is the tallest head of state?
6. Who is the tallest king in the world?
7. When was Putin made president?
8. Is Sarkozy still married to Carla Bruni?
9. How many times can a Russian president be elected?

Tags

1. #years
2. #celebrations
3. #tradition
4. #actual
5. #about
6. #their
7. #george
8. #queen
9. #birthday
10. #stories
11. #official
12. #started
13. #double