Queen Elizabeth II and Prince Philip, Duke Of Edinburgh Carry Out Engagements In Windsor on April 21, 2016 in Windsor, England. Today is Queen Elizabeth II's 90th Birthday.

 Queen Elizabeth II meets the public on her 90th Birthday Walkabout on April 21, 2016 in Windsor, England. Today is Queen Elizabeth II's 90th Birthday. The Queen and Duke of Edinburgh will be carrying out engagements in Windsor.

Queen Elizabeth II meets the public on her 90th Birthday Walkabout on April 21, 2016 in Windsor, England.

Queen Elizabeth II meets the public on her 90th Birthday Walkabout on April 21, 2016 in Windsor, England. Today is Queen Elizabeth II's 90th Birthday. 

Queen Elizabeth II meets the public on her 90th Birthday Walkabout on April 21, 2016 in Windsor, England.

Queen Elizabeth II and Prince Philip, Duke of Edinburgh wave from the top of an open Range Rover on the monarch's 90th Birthday on April 21, 2016 in Windsor, England.

Britain's Queen Elizabeth II (Below L) accompanied by her husband Prince Philip, Duke of Edinburgh, drive past a statue of Queen Victoria as they greet wellwishers during a 'walkabout' on her 90th birthday in Windsor, west of London, on April 21, 2016. Britain celebrates Queen Elizabeth II's 90th birthday on Thursday, with her eldest son Prince Charles paying tribute in a special radio broadcast and Prime Minister David Cameron leading a parliamentary homage.

Queen Elizabeth II on a walkabout to celebrate the Queen's 90th Birthday on April 21, 2016 in Windsor, England. 

Queen Elizabeth II looks out from the top of an open Range Rover on the monarch's 90th Birthday on April 21, 2016 in Windsor, England.

Queen Elizabeth II and Prince Philip, Duke of Edinburgh wave from the top of an open Range Rover on the monarch's 90th Birthday on April 21, 2016 in Windsor, England.

Queen Elizabeth II looks out from the top of an open Range Rover on the monarch's 90th Birthday on April 21, 2016 in Windsor, England. 

Britain's Queen Elizabeth II (centre L) accompanied by her husband Prince Philip, Duke of Edinburgh greet wellwishers during a 'walkabout' on her 90th birthday in Windsor, west of London, on April 21, 2016. 

Queen Elizabeth II and Prince Philip, Duke of Edinburgh wave from the top of an open Range Rover on the monarch's 90th Birthday on April 21, 2016 in Windsor, England.

Britain's Queen Elizabeth II (centre L) accompanied by her husband Prince Philip, Duke of Edinburgh greet wellwishers during a 'walkabout' on her 90th birthday in Windsor, west of London, on April 21, 2016. 

Queen Elizabeth II meet well wishers on a walk about around Windsor on her 90th Birthday on April 21, 2016 in Windsor, England.

Queen Elizabeth II meets well wishers on a walk about around Windsor on her 90th Birthday on April 21, 2016 in Windsor, England. 

Queen Elizabeth II on a walkabout to celebrate the Queen's 90th Birthday on April 21, 2016 in Windsor, England. 

Queen Elizabeth II on a walkabout to celebrate the Queen's 90th Birthday on April 21, 2016 in Windsor, England.

Queen Elizabeth II on a walkabout to celebrate the Queen's 90th Birthday on April 21, 2016 in Windsor, England.

Queen Elizabeth II waves from the top of an open Range Rover on the monarch's 90th Birthday on April 21, 2016 in Windsor, England.

Queen Elizabeth II on a walkabout to celebrate the Queen's 90th Birthday on April 21, 2016 in Windsor, England.

Queen Elizabeth II on a walkabout to celebrate the Queen's 90th Birthday on April 21, 2016 in Windsor, England.

Queen Elizabeth II on a walkabout to celebrate the Queen's 90th Birthday on April 21, 2016 in Windsor, England.

Queen Elizabeth II on a walkabout to celebrate the Queen's 90th Birthday on April 21, 2016 in Windsor, England.

Queen Elizabeth II on a walkabout to celebrate the Queen's 90th Birthday on April 21, 2016 in Windsor, England. 

Queen Elizabeth II on a walkabout to celebrate the Queen's 90th Birthday on April 21, 2016 in Windsor, England.

Queen Elizabeth II looks out from the top of an open Range Rover on the monarch's 90th Birthday on April 21, 2016 in Windsor, England.

Queen Elizabeth II looks out from the top of an open Range Rover on the monarch's 90th Birthday on April 21, 2016 in Windsor, England.



 Queen Elizabeth II meets the public on her 90th Birthday Walkabout on April 21, 2016 in Windsor, England.

Britain's Queen Elizabeth II greets wellwishers during a 'walkabout' on her 90th birthday in Windsor, west of London, on April 21, 2016.

Britain's Queen Elizabeth II greets wellwishers during a 'walkabout' on her 90th birthday in Windsor, west of London, on April 21, 2016.

 Queen Elizabeth II looks out from the top of an open Range Rover on the monarch's 90th Birthday on April 21, 2016 in Windsor, England.

Queen Elizabeth II meets the public on her 90th Birthday Walkabout on April 21, 2016 in Windsor, England.

Queen Elizabeth II meets the public on her 90th Birthday Walkabout on April 21, 2016 in Windsor, England.

Queen Elizabeth II meets the public on her 90th Birthday Walkabout on April 21, 2016 in Windsor, England.

Britain's Queen Elizabeth II cuts into a cake made by Nadiya Hussein (L), winner of the Great British Bake Off during a 'walkabout' on her 90th birthday in Windsor, west of London, on April 21, 2016.

 Queen Elizabeth II meets well wishers on a walk about around Windsor on her 90th Birthday on April 21, 2016 in Windsor, England.

Britain's Queen Elizabeth II and Prince Philip, Duke of Edinburgh, unveil a plaque on her 90th birthday in Windsor, United Kingdom on April 21, 2016.

Queen Elizabeth II rides in an open top vehicle around Windsor on her 90th Birthday on April 21, 2016 in Windsor, England. 

Queen Elizabeth II meets the public during her 90th Birthday Walkabout on April 21, 2016 in Windsor, England. Today is Queen Elizabeth II's 90th Birthday

Queen Elizabeth II meets the public during her 90th Birthday Walkabout on April 21, 2016 in Windsor, England. Today is Queen Elizabeth II's 90th Birthday.

Queen Elizabeth II meets well wishers on a walk about around Windsor on her 90th Birthday on April 21, 2016 in Windsor, England.

Queen Elizabeth II, accompanied by Prince Philip, Duke of Edinburgh unveil a plaque marking The Queen's Walkway at the foot of Castle Hill during a walkabout in Windsor on Her Majesty's 90th Birthday, England.

 Burger King restaurant has changed its name to 'Burger Queen' for the day to mark the 90th birthday of Queen Elizabeth II at Tottenham Court Road on April 21, 2016 in London, England. A series of events will celebrate the occasion including gun salutes across the capital and nationwide, a royal walkabout in Windsor and the lighting of 1000 beacons.

Queen Elizabeth II and Prince Philip, Duke of Edinburgh travel through Windsor in an open top Range Rover after her 90th Birthday Walkabout on April 21, 2016 in Windsor, England.

Queen Elizabeth II attends a beacon lighting ceremony to celebrate her 90th birthday on April 21, 2016 in Windsor, England.

Prince Philip, Duke of Edinburgh and Queen Elizabeth II attend a beacon lighting ceremony to celebrate her 90th birthday on April 21, 2016 in Windsor, England. The Queen will light the principal beacon which will set in train a series of over 1,000 beacons across the country and worldwide. 

 Prince Charles, Prince of Wales speaks at a beacon lighting ceremony to celebrate the Queen's 90th birthday on April 21, 2016 in Windsor, England.

Queen Elizabeth II lights a beacon to celebrate her 90th birthday on April 21, 2016 in Windsor, England. 

Queen Elizabeth II and Prince Charles, Prince of Wales attend a beacon lighting ceremony to celebrate her 90th birthday on April 21, 2016 in Windsor, England.

Queen Elizabeth II at a Beacon Lighting to mark the Queen's 90th Birthday on April 21, 2016 in Windsor, England.

Queen Elizabeth II and Prince Charles, Prince of Wales at a Beacon Lighting to mark the Queen's 90th Birthday on April 21, 2016 in Windsor, England.

Queen Elizabeth II and Prince Charles, Prince of Wales at a Beacon Lighting to mark the Queen's 90th Birthday on April 21, 2016 in Windsor, England. 

Queen Elizabeth II and Prince Charles, Prince of Wales at a Beacon Lighting to mark the Queen's 90th Birthday on April 21, 2016 in Windsor, England. 

Queen Elizabeth II at a Beacon Lighting to mark the Queen's 90th Birthday on April 21, 2016 in Windsor, England.

Queen Elizabeth II at a Beacon Lighting to mark the Queen's 90th Birthday on April 21, 2016 in Windsor, England.

Queen Elizabeth II at a Beacon Lighting to mark the Queen's 90th Birthday on April 21, 2016 in Windsor, England.

Queen Elizabeth II at a Beacon Lighting to mark the Queen's 90th Birthday on April 21, 2016 in Windsor, England.

Queen Elizabeth II and Prince Charles, Prince of Wales at a Beacon Lighting to mark the Queen's 90th Birthday on April 21, 2016 in Windsor, England.

Queen Elizabeth II and Prince Charles, Prince of Wales at a Beacon Lighting to mark the Queen's 90th Birthday on April 21, 2016 in Windsor, England.

Queen Elizabeth II and Prince Charles, Prince of Wales at a Beacon Lighting to mark the Queen's 90th Birthday on April 21, 2016 in Windsor, England. 

Prince Philip, Duke of Edinburgh and Queen Elizabeth II attend a beacon lighting ceremony to celebrate her 90th birthday on April 21, 2016 in Windsor, England. 

 Queen Elizabeth II attends a beacon lighting ceremony to celebrate her 90th birthday on April 21, 2016 in Windsor, England.

A beacon at Whitby Abbey in North Yorkshire is lit up as part of country wide celebrations for the 90th birthday of Queen Elizabeth II on April 21, 2016 in Whitby, England. To mark the occasion, more than 1000 beacons were lit simultaneously throughout the UK, UK overseas territories and Commonwealth countries with the Queen lighting the principal beacon at Windsor Castle.

 The Queen accompanied by Prince Charles, The Prince of Wales, lights a beacon to celebrate Her Majesty's birthday on April 21, 2016 in Windsor, England. 

 The Queen, accompanied by The Prince of Wales arrives to light a beacon to celebrate Her Majesty's birthday on April 21, 2016 in Windsor, England. 

Queen Elizabeth II attends a beacon lighting ceremony to celebrate her 90th birthday on April 21, 2016 in Windsor, England.

(R-L) Queen Elizabeth II, Prince Philip, Duke of Edinburgh and Camilla, Duchess of Cornwall attend a beacon lighting ceremony to celebrate the Queen's 90th birthday on April 21, 2016 in Windsor, England.

(R-L) Queen Elizabeth II, Prince Philip, Duke of Edinburgh and Camilla, Duchess of Cornwall attend a beacon lighting ceremony to celebrate the Queen's 90th birthday on April 21, 2016 in Windsor, England. 

Queen Elizabeth II and Prince Charles, Prince of Wales attend a beacon lighting ceremony to celebrate the Queen's 90th birthday on April 21, 2016 in Windsor, England.

Queen Elizabeth II and Prince Charles, Prince of Wales attend a beacon lighting ceremony to celebrate the Queen's 90th birthday on April 21, 2016 in Windsor, England.

 A beacon lighting ceremony against Windsor Castle to celebrate Queen Elizabeth II 90th birthday on April 21, 2016 in Windsor, England.

A picture taken on April 21, 2016 shows Queen Elizabeth II projected on the Rock of Gibraltar to mark her 90th birthday. Queen Elizabeth II is set to celebrate her 90th birthday on April 21, with a family gathering and a cake baked by a reality television star, as a new poll finds Britain's longest serving monarch is as popular as ever. The queen has reigned for more than 63 years and shows no sign of retiring, even if she has in recent years passed on some of her duties to the younger royals

Britain's Queen Elizabeth II (R) and Prince Charles, Prince of Wales (L) look at a beacon lit in honour of the Queen's 90th birthday in Windsor on April 21, 2016. 

(L) Prince Charles, Prince of Wales attends a beacon lighting ceremony to celebrate the Queen's 90th birthday on April 21, 2016 in Windsor, England.

Prince Charles, Prince of Wales and Camilla, Duchess of Cornwall attend a beacon lighting ceremony to celebrate Queen Elizabeth II's 90th birthday on April 21, 2016 in Windsor, England. 

Prince Charles, Prince of Wales and Camilla, Duchess of Cornwall attend a beacon lighting ceremony to celebrate Queen Elizabeth II's 90th birthday on April 21, 2016 in Windsor, England. 

Prince Charles, Prince of Wales and Camilla, Duchess of Cornwall attend a beacon lighting ceremony to celebrate Queen Elizabeth II's 90th birthday on April 21, 2016 in Windsor, England.

Queen Elizabeth II and Prince Charles, Prince of Wales attend a beacon lighting ceremony to celebrate her 90th birthday on April 21, 2016 in Windsor, England.

Camilla, Duchess of Cornwall attends a beacon lighting ceremony to celebrate Queen Elizabeth II's 90th birthday on April 21, 2016 in Windsor, England. 

 Prince Charles, Prince of Wales and Camilla, Duchess of Cornwall attend a beacon lighting ceremony to celebrate Queen Elizabeth II's 90th birthday on April 21, 2016 in Windsor, England.

Prince Charles, Prince of Wales attends a beacon lighting ceremony to celebrate Queen Elizabeth II's 90th birthday on April 21, 2016 in Windsor, England.

Camilla, Duchess of Cornwall attends a beacon lighting ceremony to celebrate Queen Elizabeth II's 90th birthday on April 21, 2016 in Windsor, England.

Camilla, Duchess of Cornwall and Prince Philip, Duke of Edinburgh attend a beacon lighting ceremony to celebrate Queen Elizabeth II's 90th birthday on April 21, 2016 in Windsor, England.

Prince Charles, Prince of Wales attends a beacon lighting ceremony to celebrate Queen Elizabeth II's 90th birthday on April 21, 2016 in Windsor, England. 

A beacon lit by Queen Elizabeth II to mark her 90th birthday on April 21, 2016 in Windsor, England. The Queen will light the principal beacon which will set in train a series of over 1,000 beacons across the country and worldwide.

Camilla, Duchess of Cornwall and Prince Philip, Duke of Edinburgh attend a beacon lighting ceremony to celebrate Queen Elizabeth II's 90th birthday on April 21, 2016 in Windsor, England. 

Camilla, Duchess of Cornwall attends a beacon lighting ceremony to celebrate Queen Elizabeth II's 90th birthday on April 21, 2016 in Windsor, England.

Queen Elizabeth II attends a beacon lighting ceremony to celebrate her 90th birthday on April 21, 2016 in Windsor, England. 

Queen Elizabeth II attends a beacon lighting ceremony to celebrate her 90th birthday on April 21, 2016 in Windsor, England.

Camilla, Duchess of Cornwall attends a beacon lighting ceremony to celebrate Queen Elizabeth II's 90th birthday on April 21, 2016 in Windsor, England.

Camilla, Duchess of Cornwall and Prince Philip, Duke of Edinburgh attend a beacon lighting ceremony to celebrate Queen Elizabeth II's 90th birthday on April 21, 2016 in Windsor, England.