Prince George looked smart in his uniform as he walked nervously into school on his first day – without his mother, the Duchess of Cambridge, by his side.

Kate had hoped to join the Duke of Cambridge on the school run but is suffering from severe morning sickness and was too ill to attend, Kensington Palace said.

The four-year-old prince was helped out of the car by William after being driven through the gates of Thomas’s Battersea, a fee-paying independent school in south London.

Prince George is led into school by the Duke of Cambridge and head of the lower school Helen HaslemPrince George is led into school by the Duke of Cambridge and head of the lower school Helen Haslem (Kensington Palace/PA)

The prince will be known as George Cambridge to his classmates, the palace said.

George looked tentative, clutching his father’s hand, as he was led towards the entrance of the school after arriving at around 8.45am.

The young prince shook hands with Helen Haslem, head of the lower school, as the Duke held his school bag ready for his first day.

Prince George is welcomed to Thomas's Battersea by the head of the lower school Helen HaslemPrince George is welcomed to Thomas’s Battersea by the head of the lower school Helen Haslem (Kensington Palace/PA)

Then, with William holding one hand and Ms Haslem the other, he walked inside.

The Duke told Ms Haslem that George had been eagerly watching and “noticed” the other boys going into school in their uniforms.

It is understood William and Kate will try to do the school run as often as possible.

Prince George arrives with the Duke of Cambridge at Thomas's Battersea in London, as he starts his first day of schoolPrince George arrives with the Duke of Cambridge at Thomas’s Battersea in London, as he starts his first day of school (Richard Pohle/The Times/PA)

The prince, who was wearing a shirt, navy V-neck pullover, shorts and black shoes on his first day, is thought to be one of the youngest in his year.

He is expected to have a gentle introduction to what is likely to be a tiring first term at school.

Along with his classmates, he will spend the day getting to know teachers, adults and other children as well as completing the important task of finding his classroom peg.

Prince George looked tentative just before he went into the classroom for the first timePrince George looked tentative just before he went into the classroom for the first time (Richard Pohle/The Times/PA)

Kate was forced to pull out of two public engagements on Monday and Tuesday after suffering from hyperemesis gravidarum, as she did in her previous pregnancies.

On Tuesday, a day after it was announced they are expecting their third child, William said Kate was well but admitted: “There’s not much sleep going on at the moment.”

He said: “We need Catherine to get over this first bit and then we can start celebrating. It’s always a bit anxious to start with, but she’s well.”

The Duke of Cambridge on Prince Harry's first day at school with their mother Princess DianaThe Duke of Cambridge on Prince Harry’s first day at school with their mother Princess Diana (Ron Bell/PA)

George’s new school, where fees cost from £17,604 a year, has been 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.

“That is what they want and, to a large degree, that is what they get.”

The young prince and his classmates will be taught a range of subjects and activities from ballet and art to drama, French, music and physical education.

Kate has already said she is not sure her son “has any idea what’s going to hit him” when he starts school.

The Duke of Cambridge hopes to do as many school runs as possibleThe Duke of Cambridge hopes to do as many school runs as possible (Richard Pohle/The Times/PA)

Ben Thomas, who is principal of Thomas’s London Day Schools and was headmaster of Thomas’s Battersea for 18 years, said he hoped future king George would learn to “be himself”.

He said: “The whole aim of these precious early years of education is to give children that confidence in who they are.

“So we are not going to try to mould him into any kind of particular person and we wouldn’t do that with any of our pupils.

“I hope he will have the confidence to be himself with all his quirks and his idiosyncrasies and characteristics.”

Here are 10 things to know about Prince George's new school:

1. Fees at Thomas's Battersea cost £17,604 a year and increase in year 3. If George stays at the selective establishment throughout, until the end of Year 8 when he turns 13, the total cost will be £172,116.

2. The school's most important rule is ''Be kind''. It expects its pupils "not just to tolerate but to celebrate difference, including faith, beliefs and culture".

3. The school also teaches leadership. "We aim to equip our pupils to lead by example; to be prepared to stand out from the crowd; to be the first to respond to someone in need; to stand up for what they believe to be right; to risk making an unpopular decision, if they believe it to be for the greater good," it says.

4. It has also reportedly discouraged pupils from having best friends, in order to stop others from having their feelings hurt.

5. George will enjoy small class sizes of about 20 pupils. The average class size for primary schools in England is around 27 children.

6. The Prince will be learning ballet - along with French, art, drama, ICT and music, as well as the Early Years Foundation Stage curriculum.

7. Uniform is compulsory, including smart, pulled up red socks and navy bermuda shorts.

8. George must have a red art smock, which costs from £30, a swim hat and a PE kit.

9. Parents are advised to register their child soon after birth to be in with a chance of going to the oversubscribed school. Wannabe reception pupils are given an entrance assessment before being offered a place.

10. The school dinners are often organic. Previous menu choices range from freshly baked courgette, halloumi and beetroot layer slice, to Marine Stewardship Council (MSC) certified pangasius, leek and spring onion risotto, and oven baked beef meatballs with cannellini beans in a tomato and basil sauce with grated organic cheese and fresh crudities and steamed 50/50 brown and white rice.