The Duke of Edinburgh has said he is "disappointed" after being taken to hospital.
Prince Philip had been at Windsor Castle when he was admitted as a "precautionary measure" for treatment of an infection arising from a pre-existing condition, Buckingham Palace have said.
He had been due to accompany the Queen to today's State Opening of Parliament but the Prince of Wales will now do so.
Prince Philip is in good spirits and is disappointed to be missing the State Opening of Parliament and Royal Ascot.
Her Majesty is being kept informed and will attend Royal Ascot as planned this afternoon."
Royal Mail is issuing a new set of special stamps featuring three windmills and three watermills from around the UK.
The set is made up of stamps featuring: Nutley Windmill, East Sussex; New Abbey Corn Mill, Dumfries and Galloway; Ballycopeland Windmill, County Down, Northern Ireland; Cheddleton Flint Mill, Staffordshire; Woodchurch Windmill, near Ashford, Kent and Felin Cochwillan Mill, Gwynedd.
Windmills were first referred to in East and South East England in records dating from the 12th century, and had become widespread throughout Britain by the end of the 13th century.
It is with great sadness that we announce the death of the Countess Mountbatten of Burma.
Patricia Mountbatten died peacefully on Tuesday 13 June at her home in Mersham, Kent, surrounded by her children. Her husband, the celebrated film producer Lord Brabourne, died in 2005.
The arrangements for a funeral in London followed by a burial service in Mersham will be announced in due course.
The Queen and the Duke of Edinburgh are among the very first to travel on one of the new high speed Hitachi trains being built for the region.
It was a milestone for the massive project to upgrade the Great Western network.
The scheme aimed at easing some of the worst crowding in the country remains late and over budget.
But the new trains will start to enter service later in the year.
They will eventually run from Paddington to Reading, Newbury, Didcot, Bedwyn, Swindon, Bath, Bristol and through to Wales and Devon and Cornwall.
Our Transport Correspondent MIke Pearse has been talking to commuters who say the improvements can't come soon enough.
Mike spoke to Paul Gentleman from Great Western Railway and Chris Irwin from Travelwatch South West.
Her great-great-grandmother, Queen Victoria, was the first ever British royal to take a train journey.
Today, 175 years later, the Queen along with the Duke of Edinburgh recreated that very same trip on the Great Western line travelling from Slough in Berkshire to Paddington.
It's fair to say, things have changed a bit since 1842.
As Mel Bloor reports.
Mel spoke to Isambard Thomas and Mark Hopwood from Great Western Railway.
- Watch Mel Bloor's full report here
The Queen will today mark the 175th anniversary of the first train journey made by a British monarch.
On 13 June 1842 Queen Victoria made the trip from Slough to Paddington, writing in her journal afterwards that it was "delightful and so quick".
The Queen and the Duke of Edinburgh are due to embark on the same journey on the day of the anniversary - this time as the first passengers on one of the region's new Hitachi high speed trains.
The Duchess of Cornwall was the guest of honour today at the South of England Show at Ardingly in Sussex.
The royal even took time out of her schedule to 'knight' one of the visitors - the actor Callum Arnott. In the absence of a sword, a Sussex-grown leek was used to mark the occasion.
The three-day event is celebrating its 50th year at the Ardingly showground and though the skies were heavy and grey, the rain held off, and the crowds turned up. Derek Johnson reports
His Royal Highness Prince Charles visited the family home of Sir Winston Churchill, Chartwell in Kent this morning.
The National Trust has embarked on an ambitious plan this year to purchase hundreds of historic artefacts belonging to the wartime prime minister and secure them as part of his public legacy.
They're on display at his family home of Chartwell near Westerham and today Prince Charles made a special visit to take a look around. Sarah Saunders report contains some flash photography.
Prince Charles has been visiting Chartwell in Westerham this morning. His Royal Highness has been to see the results of the Trust's work to restore the former family home of Winston Churchill. Chartwell welcomes almost a quarter of a million visitors every year.