Prince George is to begin his first day at school – but it is not clear whether his mother, the Duchess of Cambridge, will be well enough to take him.
Kensington Palace said a decision on whether Catherine, who is suffering from severe morning sickness, will drop him off will be made this morning.
The four-year-old will attend Thomas’s Battersea, a £18,000-a-year preparatory school in south-west London.
His uniform includes navy shorts and jacket, long red socks and black shoes.
The milestone for the prince comes after the Duke and Duchess of Cambridge this week announced they are expecting their third child.
Catherine had to pull out of public engagements on Monday and Tuesday because she is suffering from hypremesis gravidarum, as with her previous two pregnancies.
Prince George will follow in the footsteps of his father and uncle, Prince Harry, who both attended preparatory school at a young age.
Notable alumni at Thomas’s Battersea include pop singer Florence Welch – from Florence and the Machine – model and actress Cara Delevingne, and Fresh Meat star Charlotte Ritchie.
His new school was described by the Good Schools Guide as: “A big, busy, slightly chaotic school for cosmopolitan parents who want their children to have the best English education money can buy.”
Navy Bermuda shorts
Previously, Prince George attended nursery at the Westacre Montessori School, in Norfolk.
However, his move to London coincides with the duke and duchess’s decision to begin moving their main residence to Kensington Palace, as Prince William takes on more royal duties.
Prince George, who is often pictured wearing shorts and knee-high socks, will continue this sartorial staple at Thomas’s.
Pupils in reception class wear red polo neck shirts, navy Bermuda shorts and knee-high red socks with navy trimming.
The prince will also wear a v-neck jersey emblazoned with the Thomas’s emblem, as well as a navy jacket.
Former headmaster Ben Thomas said the school was “honoured” to have been chosen by the royals.
It is expected that one cameraman and one photographer will be at the school to capture the moment, as Prince William has previously pleaded for the press to respect his son’s privacy.
Royal commentator Richard Fitzwilliams said: “William is determined to give his family as much privacy as possible and have a life as ‘normal’ as possible but this is extremely difficult.
The royals have made several complaints to IPSO [the Independent Press Standards Organisation].
“They are in the royal ‘goldfish bowl’ and will continue to be the centre of national and international fascination.”
Princes William and Harry – who were also photographed on their first days at school – went to the Wetherby School in Kensington, before both going on to Eton College, in Berkshire.
Their father, Prince Charles, was initially educated at home by a governess, but later attended the Cheam Preparatory School, in Berkshire.
No media frenzy as royals plea for privacy
By Peter Hunt, royal correspondent
When Prince George enters the school building, at the start of his first day there, the moment will be captured by one photographer and one camera crew.
When his father made a similar journey, to a different school, three decades ago many more members of the media were present to record a fresh developmental stage in the life of a future king.
Prince William remembers and doesn’t want history to repeat itself.
George’s schooling will be the latest test of the Cambridge’s wary relationship with the press. They expect reporters to respect the privacy of their son and his classmates.
Attending school is a relatively new phenomenon for the House of Windsor.
Boarding school was ruled out for the home-educated Queen over fears she couldn’t be “protected from bad influences”.
And Prince Charles’s first teacher – before going to school aged eight – was a governess who taught him in a room at Buckingham Palace that contained a blackboard and a desk.