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 seven 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.
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.
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.