The Queen at 90:Photos

Tributes are pouring in to mark the 90th birthday celebration of the Queen. "The Queen has been a rock of strength for our nation and the Commonwealth", Prime Minister David Cameron has said in a tribute to mark her 90th birthday. The Prince of Wales has recorded a special radio broadcast for the day, in which he reads an edited passage from William Shakespeare's Henry VIII.

Her Majesty The Queen celebrates two birthdays every year: her actual birthday on 21 April and her official birthday on a Saturday in June. On Wednesday 20 April, the Queen carried out two engagements in Windsor. With the Duke of Edinburgh, she visited the town's Royal Mail delivery office to mark the 500th Anniversary of the postal service and she officially opened the new bandstand in Windsor's Alexandra Gardens.

The Queen is due to spend her birthday today, at Windsor Castle. Well-wishers will have the chance to wish her many happy returns as she unveils a plaque on the Queen's Walkway. The Queen is also scheduled go on a walkabout with the Duke of Edinburgh to meet members of the public.

Then, at 12:00 BST, gun salutes will be held at saluting stations across the UK, including at Hillsborough Castle, Cardiff Castle, and Edinburgh Castle.

This evening, she will light a beacon setting in train a series of more than 850 beacons across the UK and around the world to mark the milestone birthday.

The images, taken by celebrity photographer Annie Leibovitz, reveal the queen with other members of her family. Photos by i-images and Sion Touhig/Getty images. 

Culled from The Guardian UK.