Thursday marks Queen Elizabeth II's 90th birthday, and her big day is already off to an amazing start. The head of the royal family, who will be celebrating the milestone again in June, stepped out in Windsor, England, on April 21 for her very own "walkabout." Massive crowds gathered to line the streets to get a glimpse of the queen, who is set to partake in a slew of birthday engagements near one of her homes, Windsor Castle. The big outing comes on the heels of the release of the family's new postage stamps, which feature a smiley Prince George, and her own portrait with all of her grandkids. Browse our recent collection of Queen's Birthday images, Queen's Birthday wallpaper. Get access to all happy 90th birthday images, queen band pictures, Queen's Birthday images, Queen's Birthday wallpaper, Queen's Birthday hd images, Queen's Birthday photos, Queen's Birthday download, Queen's Birthday gallery.