The Duke and Duchess of Cambridge announced the happy news that they welcomed their third child together on Monday 23 April – a baby boy. Kate was admitted to hospital in the early hours of Monday morning, with the news announced by Kensington Palace shortly before 8:30am. She welcomed her son at 11.01am, and the news was announced two hours later.
MORE: Watch live royal baby updates from the Lindo Wing
The official statement read: "Her Royal Highness The Duchess of Cambridge was safely delivered of a son at 1101hrs. The baby weighs 8lbs 7oz. The Duke of Cambridge was present for the birth. Her Royal Highness and her child are both doing well." A second tweet read: "The Queen, The Duke of Edinburgh, The Prince of Wales, The Duchess of Cornwall, Prince Harry and members of both families have been informed and are delighted with the news."
STORY: Prince George and Princess Charlotte arrive to meet their baby brother
Fans of the royal family have been eagerly awaiting the arrival of the royal baby ever since the barriers were set up ahead of the birth at the Lindo Wing on 9 April, with many camping outside the hospital for two weeks in anticipation of Kate's labour. Click through the gallery to see all of the best photos from the historic day…
The Duke and Duchess of Cambridge held hands as they left the hospital. Their baby boy slept soundly while wrapped up in a white blanket in his car seat, ahead of his journey back to Kensington Palace.
Prince William and Kate's baby boy looked adorable as he slept in his car seat before travelling home to Kensington Palace. The Prince was wrapped up in a white hat and blanket for his public debut.
She may have just welcomed her third child only hours earlier, but the Duchess of Cambridge looked impeccably stylish as ever when she left the hospital with Prince William by her side. The 36-year-old wore a red Jenny Packham dress and nude heels, with her brunette hair in a bouncy blow dry.
How adorable is our new baby Prince?! The Duke and Duchess of Cambridge cradled their bundle of joy, who was born weighing 8lb 7oz, on the steps of the Lindo Wing before returning home on Monday evening.
New mum Kate gazed down at her baby boy as they introduced him to the world for the first time on Monday afternoon. The Duchess looked radiant as she stepped out in a red Jenny Packham dress which featured a lace Peter Pan collar.
Prince William affectionately stroked Prince George's head as they entered the Lindo Wing, where the children would have the opportunity to meet their baby brother for the first time. The proud dad was still holding hands with daughter Princess Charlotte, two, who delighted the crowds by waving on her way to the hospital.
Princess Charlotte turned back to wave again to the crowds before entering the hospital. The two-year-old looked adorable in a blue floral dress and navy cardigan, and appeared excited at the prospect of meeting her baby brother.
Prince William returned to the hospital after 30 minutes with Prince George and Princess Charlotte in tow. George, four, looked adorable in his school uniform, while Charlotte, two, delighted crowds by waving sweetly as they made their way into the hospital.
Prince William held Prince George's hand as he got out of the car, while the crowds all tried to capture photos of the young royal. George, four, was still dressed in his school uniform, and appeared a little overwhelmed by the attention they received.
Prince William looked delighted as he left the Lindo Wing, five hours after the royal baby's birth. The Duke reassured crowds that he would be "back in a minute" as he got into a waiting car to collect his children Prince George, four, and Princess Charlotte, two, to come and meet their baby brother.
An overjoyed Prince William waved to the crowds of media and well-wishers who had been waiting outside the hospital all day. The new dad couldn't stop smiling as he made his way into a waiting car, before collecting Prince George and Princess Charlotte.
Crowds outside the Lindo Wing were surprised to catch a glimpse of the Queen driving past - although all was not as it seemed! A waxwork of the monarch was sat in the back of a black cab that drove down the road past the hospital on Monday afternoon.
An easel was placed in the forecourt of Buckingham Palace to officially announce the birth of Prince William and Kate's baby boy. Just like with Prince George and Princess Charlotte, the easel shared the official statement from Kensington Palace and was signed by the hospital team who tended to the Duchess. The easel will remain in place for around 24 hours.
The practice of posting a bulletin announcing a royal birth has gone on for at least as long as Buckingham Palace has been the Sovereign's official residence - since 1837. After it comes down, the notice will be sent to the Privy Council Officeso it can be kept in their records.
A self-proclaimed royalist town crier arrived on the steps of the Lindo Wing to announce the safe arrival of Prince William and Kate's baby boy. "God save the Queen!" he shouted, to cheers from the crowds of media and fans who were gathered outside.
People around the word celebrated the news that Prince William and Kate had welcomed a baby boy. Among them were the Royal Marines on board HMS Albion, who spelled out the word 'BOY' on the assault ship's flight deck, whilst deployed in the Far East.
Photo: Dave Jenkins/Royal Navy/MoD/Crown copyright/PA Wire
The BT Tower celebrated the royal baby's arrival with a special announcement: "It's a boy!" a blue screen read at the top of the tower.
Even before the birth of the royal baby was announced, fans were placing bets on what Prince William and Kate would choose to name their third child. Arthur, James and Albert were among the most popular names for a boy, while Alice and Mary are hotly-tipped names for a girl.
A couple of new parents were greeted by the world's press as they left the Lindo Wing with their newborn child. The couple smiled for photographers on the steps of the private hospital, where Prince William and Kate are expected to step out for the first time with their royal baby later on Monday.
Fans excitedly waved HELLO! Union Jack flags as they awaited the announcement that the royal baby had been born. Hundreds of people travelled across London to be outside the Lindo Wing at St Mary's Hospital for the historic occasion, following Kensington Palace's announcement that Kate was in labour early on Monday morning.
By midday, the number of press congregated at the hospital extended along the road, with hundreds of reporters and photographers around the world gathered in the press pen in anticipation of the royal baby announcement. Among them was HELLO!'s royal correspondent Emily Nash, who had an amazing position alongside the UK press in front of the Lindo Wing doors.
Political artist Kaya Mar arrived outside the Lindo Wing on Monday morning, carrying a painting depicting the Duke and Duchess of Cambridge in a religious context with their children Prince George and Princess Charlotte, and the royal baby.
Royal enthusiasts had camped outside the hospital for almost two weeks before Kate was admitted on Monday morning, including Terry Hut (pictured). The group, many of whom were also present for the births of both Prince George and Princess Charlotte, were dressed patriotically in Union Jack flags and red, white and blue to mark the royal baby's arrival, which came on St George's Day.
The group told reporters that they were particularly excited that the royal baby would be born on St George's Day. John Loughrey, 63, who is part of a group who have been camped outsidethe hospital, said: "We are so pleased. We have been here for 15 days. I'm so pleased it's St George's Day. St George himself would be very pleased if the baby's born today."
Police officers stood guard outside the Lindo Wing of St Mary's Hospital in Paddington, as crowds began to gather following the announcement that the Duchess of Cambridge had been admitted in the early hours of Monday morning.
Within an hour of the announcement that Kate was in labour, press and photographers all started to congregate outside the Lindo Wing at St Mary's Hospital in order to get the best glimpse of the royal baby's debut. The barriers had been in place for two weeks ahead of the baby's arrival.