Queen Elizabeth II
The first engagements of this party season come today as the Queen and the Duke of Edinburgh carry out several engagements in Windsor. They are due to visit the Royal Mail Sorting Office there to help mark the 500th anniversary of the Postal Service before officially opening the new bandstand at Alexandra Gardens near Windsor Castle. Ahead of the visit to the postal service, Royal Mail released a new photo of four generations of royalty which will feature on special stamps being issued for the Queen's 90th birthday and which are available to buy via their website and post offices.
The Queen, the Prince of Wales, the Duke of Cambridge and Prince George of Cambridge in a new image for the history books
On the big day itself, the Queen and the Duke of Edinburgh will enjoy a walkabout in Windsor to meet as many wellwishers as possible - and there will be plenty who want to help celebrate this monarchical milestone birthday. And no royal event would be complete without a plaque to unveil so the Queen will be doing the honours for the Queen's Walkway, a 6.3 kilometre trail through Windsor developed to mark the moment she became Britain's longest reigning monarch in 2015. Royal fans are already in place in Windsor for the celebrations.
And then there are the beacons. As dusk falls on April 21st 2016, the Queen will light the first of thousands of beacons which will blaze around the country to celebrate her 90th birthday. Lighting bonfires like this is one of the oldest ways of celebrating big royal events and it will add yet more history to this special day. The Duke of Edinburgh, the Prince of Wales and the Duchess of Cornwall will accompany the Queen for this big moment with reports that Charles will be hosting a private party for his mother afterwards to mark her birthday.
The rest of us can settle down to watch another special programme on the Queen at 90, this time on BBC One. And that night's news will no doubt carry reports of the gun salutes at Tower Hill and Green Park which will mark the Queen's 90th. There will also be peals of bells from Westminster Abbey to celebrate the Royal Birthday.
The Queen in a special image from the BBC One programme being shown to mark her 90th birthday
The Queen doesn't get much chance for a sit down - on April 22nd, she is hosting the President and the First Lady of the United States of America for lunch where no doubt there will be more celebrations and congratulations from Barack and Michelle Obama who have always enjoyed a warm relationship with Elizabeth II>
The party continues in May when the Queen's 90th Birthday Celebration takes place at Windsor Home Park. That four day event is centred around horses. The main national celebrations take place in June when there is a special service at St Paul's Cathedral in London in thanksgiving for the Queen's 90th birthday and the 95th birthday of the Duke of Edinburgh which takes place that month.
That celebration is on June 10th, one day before Trooping the Colour which marks the Queen's official birthday. The following day there is a huge party in the Mall for thousands of guests. It's going to be some celebration. Sit back and enjoy.
There is a special page about the Queen's 90th birthday here.