The Duke of Edinburgh, who turns 97-years-old tomorrow, was absent from Trooping the Colour this morning.
Prince Philip, who retired from public duties last year, only now attends the occasional event as and when he feels like he is able to.
It was thought that Trooping the Colour would have been one of the few occasions Prince Philip would continue attending. However, it is very likely he will be watching the proceedings from home.
The Queen cut a lonely figure as she travelled to Horse Guards from Buckingham Palace in a carriage on her own.
She was followed in the carriage by the Prince of Wales, Princess Royal, Duke of Cambridge and for the first time, the Duke of York on horseback.
It is not known whether Prince Philip will appear on the balcony of Buckingham Palace for the traditional RAF flypast at 1pm.
Also absent from the ceremony today was the Earl of Wessex who is currently on a tour of China. His wife and daughter attended the event in a carriage alongside Princess Beatrice and Eugenie.
At the event itself, The Queen sat next to her cousin, the Duke of Kent in the absence of her husband.
The 82-year-old Duke was wearing his military uniform this year. In 2017 he opted for a top hat and suit in favour of his heavy bearskin, possibly because of the hot temperatures.