Queens Windsor Castle
The Queen normally spends weekdays at Buckingham Palace during working periods of the year, but has decided to stay at Windsor, which she prefers, where she will personally open a selection of birthday cards sent to her from around the world.
Like the Duke of Edinburgh, the Queen dislikes the idea of anyone “making a fuss” over her birthday, and any family celebration is likely to be a low-key affair.
It is the fourth successive year that the Queen has celebrated her birthday privately at Windsor, though two of her previous three birthdays were on a weekend.
The Queen is already the world's oldest reigning monarch
Her 85th birthday fell on Maundy Thursday, when Her Majesty gave out Maundy money at a service in Westminster Abbey, and on her 80th birthday she went on a walkabout in Windsor to greet crowds who had gathered the celebrate the milestone.
The Queen will be back in action on Saturday, when she attends a service at Westminster Abbey to mark the centenary of the Gallipoli campaign in the First World War.
A 41-gun salute will be fired by the King’s Troop Royal Horse Artillery from Green Park in central London at midday to mark the occasion.