The Queen at 90: The most important photo from every single year of her remarkable life

In her 90 years, the record-breaking monarch has pretty much seen it all - she has undertaken more than 260 official overseas visits, has given audience to 12 British Prime Ministers and met 12 U.S presidents.

On the day of her birthday - April 21 - she will spend most of her time at home in Windsor castle. In the evening, she'll light the first in a chain of 1,000 beacons around the world that will celebrate her birthday, before hosting a private luncheon for Barack Obama and his wife Michelle the following day.

In celebration of her 90th birthday, we've found a photo from every single year of her remarkable life.