Kensington Palace delighted the nation in September 2017 when it announced that the Duke and Duchess of Cambridge were expecting their third child.
The Duchess of Cambridge, who is currently eight months pregnant, is due to give birth in April - although the precise date is unknown.
Here's everything royal-watchers need to know about the new addition to the royal family, from delivery hospital to potential names.
Read the press release in full ↓ pic.twitter.com/vDTgGD2aGF— Kensington Palace (@KensingtonRoyal) September 4, 2017
When will the royal baby be born?
Kensington Palace tweeted the nation in October to reveal that the Duchess of Cambridge is due to give birth in April.
The Duchess was compelled to bring forward her third pregnancy announcement in September after being too unwell to attend a planned public appearance due to Hyperemesis Gravidarum - severe morning sickness.
Both Prince George, four, and Princess Charlotte, two, are thought to have been born slightly late: in 2015 the Duchess of Cambridge let slip that her due date was towards the end of April, however Princess Charlotte was born on 2 May. This might mean another longer-than-average pregnancy is on the cards for the Duchess.
The new royal arrival will come just weeks before Prince Harry and Meghan Markle tie the knot on Saturday, May 19 at St George's Chapel in Windsor Castle, hopefully giving Kate a few days to recover.
Where will the royal baby be born?
Both Prince George and Princess Charlotte were born at the Lindo Wing of St Mary's Hospital in Paddington, west London, making it likely that their sibling will also be born there.
The private wing of the NHS hospital charges £5,215 for the first 24 hours if a baby is born naturally, or £6,745 for a Caesarean section, plus £1,155 for the deluxe package for each additional night.
The Telegraph's Anna Maxted had all three of her children there, and describes the rooms as basic, but the care as first-class.
When the Duchess of Cambridge was pregnant with Princess Charlotte in 2015, contingency plans were put in place. If the Duchess unexpectedly went into labour while visiting her parents in Bucklebury, she would have been taken to the Royal Berkshire Hospital in Reading, while if she went into labour at Anmer Hall, the couple's country residence in Norfolk, she would have given birth at the Queen Elizabeth Hospital in King's Lynn.
What names could the Duke and Duchess of Cambridge be considering?
The Duke and Duchess have chosen solidly traditional royal names for their children in the past, making it likely they will reference previous monarchs this time as well.
However, here’s one former king who's highly unlikely to ever have another royal namesake: King John. That’s because in his short 17-year reign he managed to so sully his name it's pretty much been removed from royal circulation.
Not only was he exceptionally rapacious and cruel (he had a penchant for starving his enemies to death), John was also one of the most cowardly and incompetent scoundrels to sit on the throne.
The couple's first child George will in time become King George VII, following a tradition dating back to German-born George I, the first Hanoverian king of Great Britain who acceded to the throne in 1714. The last was the Queen's father George VI who died in 1952 but was known to his family as Bertie.
Among the previous monarchs to have had the name is George III - on the throne from 1760 to 1820 - who is predominantly remembered for losing the American colonies and his sanity. However, the Prince of Wales has previously disclosed that he is the king he most respects, describing him as a good man who was simply misunderstood.
The Duke and Duchess of Cambridge honoured both royal tradition and family ties by naming their second child Charlotte.
The name’s royal pedigree includes Queen Charlotte, the wife of George III, who bore him 15 children and helped found Kew Gardens. Queen Charlotte’s & Chelsea Hospital, which is named after her, is part of the same NHS Trust as St Mary’s Hospital Paddington, where the private Lindo Wing is situated.
Her granddaughter Princess Charlotte of Wales, who married on May 2, the day the new Princess Charlotte was born, died in childbirth in 1817 at the age of just 21. She was the only child of George, Prince of Wales, who would go on to become King George IV.
Charlotte also happens to be the middle name of the Duchess’s sister, Pippa Middleton, and goes back in her family to her paternal great-great-great-grandmother Charlotte Ablett, born in 1825 and therefore possibly named for Princess Charlotte.
So what are the options?
Leading bookmaker Coral is continuing to see a flurry of bets on Mary - it is now the 4-1 favourite. Alice is second best in the latest betting, Victoria is 8-1 and Albert can be backed at 12-1.
Mary is one of the Queen's middle names, and it was also her grandmother's name - Queen Mary - who was married to George V.
How will this affect the succession?
The new royal baby will be fifth in line to the throne, behind the Prince of Wales, the Duke of Cambridge, Prince George and Princess Charlotte. It means Prince Harry will drop down to sixth in line, and every other member of the Royal family will be one step further away from the throne.
Because of recent changes to the laws governing succession, the baby's sex will make no difference, as boys no longer have precedence over girls. If the change hadn't been made and the third baby were a boy, he would be fifth in line instead of Princess Charlotte - however that will now not be the case.
Will the Duchess of Cambridge have a natural birth?
Both Prince George and Princess Charlotte are believed to have been born by a natural delivery, meaning the Duchess of Cambridge will presumably be planning to have a natural birth this time as well.
In 2015 Pat O'Brien, a consultant obstetrician at University College Hospital, said that because of the speed with which the Princess Charlotte was delivered after the Duchess was admitted to hospital, it is likely that she went into labour naturally.
He said: "The fact that she went into hospital at around 6am and had the baby by 8.34am would not imply that she was induced at all.
"Second time labours tend to be quicker than first time labours. Everything tends to go faster. The dilation stage is quicker, the pushing stage is usually quicker and easier as well, and the baby comes out more quickly. You would expect it to be an easier labour anyway."
Who will deliver the royal baby?
The medical team in charge of safely delivering Princess Charlotte was led by Guy Thorpe-Beeston, Surgeon Gynaecologist to the Royal Household.
Mr Thorpe-Beeston, an obstetrician who specialises in high-risk pregnancies, has a private Harley Street practice and is a consultant at the Portland private hospital and at the Chelsea and Westminster Hospital in the NHS.
A Cambridge graduate, he worked at King's College Hospital in London before becoming a consultant in foetal medicine at Chelsea and Westminster in 1996.
He was assisted by Alan Farthing, Surgeon Gynaecologist to the Queen, who was the fiance of the television presenter Jill Dando at the time of her murder in 1999, and has been part of the Queen's medical household since 2008.
In 2014 Sir Marcus Setchell, the recently retired surgeon gynaecologist to the Queen who delivered Prince George, told BBC Radio 4’s Woman’s Hour: “What happened in labour is an entirely private matter, but I do think there are certain situations when someone is giving birth that it’s important…to have a specialist…in the same room to deal with anything that’s immediately going to be wrong.”
How will news of the birth be announced?
After the Queen, other members of the Royal family and the Middletons have been told the good news, the royal communications team will email media organisations with the sex, weight and timing of the birth. Moments later the news will be announced via royal Twitter and Instagram accounts before a traditional paper announcement is placed on an easel outside Buckingham Palace.
Her Royal Highness The Duchess of Cambridge was safely delivered of a daughter at 8.34am.— Kensington Palace (@KensingtonRoyal) May 2, 2015
When will we see the royal baby?
After the birth of Prince George, the Duchess left hospital the next day, while she left the hospital to go home on the same day after giving birth to Princess Charlotte.
But the length of the Duchess's hospital stay this time around will be entirely down to how she is feeling, so there is no guarantee we will see the baby within 24 hours of its birth. The Duke and Duchess are expected to leave the Lindo Wing by the front door to give the waiting media the chance to take the photographs that will no doubt adorn the front pages of newspapers the next day.
After the birth of Princess Charlotte, the Duke and Duchess spent the first nights of her life at Kensington Palace before driving north to their country home, Anmer Hall, on the Queen's Sandringham estate, where they were likely joined there by the Duchess's parents, Michael and Carole Middleton, who often stayed over to help look after Prince George.
However, the family permanently relocated to Kensington Palace last year, after deciding Prince George should be schooled in London, so it's unlikely that they'll head back to Norfolk for a while.
Will the Duke and Duchess take maternity and paternity leave?
They have on previous occasions: after the birth of Princess Charlotte, the Duke took two weeks' statutory paternity leave from his job as an air ambulance pilot, which he quit in July 2017 to become a full time royal, and the Duchess took maternity leave from her official royal duties.
After the birth of Prince George, the Duchess was back in action after five weeks, joining her husband to start the Anglesey Coastal Ultra Marathon. However, she maintained a light workload for several months after both births.
Will the Duchess hire a maternity nurse?
As well as having a full-time nanny and plenty of help from the Middletons in 2015, the Duke and Duchess of Cambridge hired another temporary nanny to help them through the first weeks of Princess Charlotte's life.
The couple were determined to manage without professional help when Prince George was born, but he was not a good sleeper and the Duchess became exhausted after countless sleepless nights.
They eventually accepted they needed help, and hired Spaniard Maria Borrallo from the world-famous Norland nanny agency when Prince George was seven months old.
When Princess Charlotte was born they reportedly made arrangements through Norland for a maternity nurse to work full-time for at least three months, to get them through the most difficult period of their new baby’s life.
Will I be able to buy lots of royal baby souvenirs?
Inevitably, the answer will be yes. Perhaps the most tasteful souvenir will be a commemorative £5 coin that is likely to be a hit with collectors.
When Prince George was born the Royal Mint produced 10,000 solid silver coins, which cost £80 each, and 2,013 22 carat gold sovereigns, priced at £800. They all sold out within days. Babies born on the same day as Prince George were also entitled to a free "lucky" silver penny minted for the occasion.
When Princess Charlotte was born the Royal Mint produced four coins, ranging in price from £13 to £1,800.
The Royal Collection Trust, which runs the official souvenir shops at royal palaces, is likely to bring out its own range of commemorative china. When Prince George was born, official plates, cups and other chinaware was on sale just two days later.
The usual unofficial range of tea towels, postcards and crockery will no doubt follow.