Prince William and Kate are seen as the new face of a centuries-old institution, keeping the best of traditions while moving forward with the times. Here are 10 things to know about the royal baby in relation to royal births of the past:
Most people take a hospital birth for granted these days, but just a few decades ago the custom among royals - as it was among commoners - was to give birth at home.
Queen Elizabeth II was born at 17 Bruton Street in London, a private family home, and she gave birth to her sons Charles, Andrew and Edward in Buckingham Palace. Her only daughter, Princess Anne, was born at Clarence House, also a royal property.
That changed by the 1980s, when Princes William and Harry were both born at the private Lindo Wing of St. Mary's hospital in central London.
For a long time, royals were educated in private. The queen was taught at home by her father, tutors and governesses, and never mingled with commoners at a school, college or university.
Charles was the first royal heir to have gone to school, and William and Kate, who were both educated at independent schools, will doubtless have their child do the same.
DADS IN THE DELIVERY ROOM
William has said he "fully intends" to be there with Kate when she gives birth, in line with the expectations of many modern parents. He follows in the footsteps of his father, Charles, who declared how much he relished being in the delivery room in a letter to his godmother, Patricia Brabourne.
"I am so thankful I was beside Diana's bedside the whole time because by the end of the day I really felt as though I'd shared deeply in the process of birth," Charles wrote shortly after William's birth.
Things were quite different when Charles was born. When the queen (then Princess Elizabeth) went into labor, her husband, Prince Philip, was off playing squash in the palace - out of restlessness, not indifference, noted Charles' biographer Jonathan Dimbleby.
In the early 1900s - and probably before - custom dictated that government officials should be present when a royal was born. When the queen was born in 1926, for example, the home secretary was present among the doctors.
The current home secretary, Theresa May, said the centuries-old tradition required the official to attend "as evidence that it was really a royal birth and the baby hadn't been smuggled in." Fortunately for Kate - the practice was abolished years ago by George VI.
The custom is thought to have been linked to the so-called "warming pan plot" of 1688, when rumors swirled that the supposed child of James II was sneaked into the delivery room in a long-handled bed-warming pan. Some 40 to 60 people were said to have dropped in to witness the birth.
HOW MANY NAMES?
Apart from the baby's gender, the biggest guessing game ahead of the royal birth has to be the name. Most royals have three to four first names, usually in a combination that honors previous monarchs or relatives. The queen's full name is Elizabeth Alexandra Mary, after her mother, great-grandmother and grandmother, and William's full name is William Arthur Philip Louis.
If you believe the bookmakers, the royal baby's first name is most likely to be Alexandra, Charlotte, Elizabeth, or George. In any case, it could take a while for the public to find out the future monarch's name. When William was born, it took a full week before his name was announced.
AND THE LAST NAME?
The royals don't require a surname. The correct title when referring to the royal baby will be His or Her Royal Highness Prince or Princess (name) of Cambridge. If required, current members of the royal household may use Mountbatten-Windsor, the surname adopted in 1960 for all of the queen's children. (That name combines Windsor, the family name adopted by King George V in 1917 to replace Saxe-Coburg-Gotha, and Prince Philip's family name, Mountbatten).
Prince William, the heir of Charles, the Prince of Wales, is known as Flight Lt. Wales when on military duty.
Royal babies tend to be officially christened several days to weeks after they are born, and there are a few potential places this could take place for the new baby.
The queen was christened in the private chapel at Buckingham Palace, while both William and his father Charles were christened in the palace's Music Room.
A PLAIN OLD EASEL VS. TWITTER
The traditional way the palace announces a royal baby's birth to the world is as quaint as it gets: A messenger with the news travels by car from the hospital to Buckingham Palace, carrying a piece of paper detailing the infant's gender, weight and time of birth. The bulletin is then posted on a wooden easel on the palace's forecourt for everyone to see.
In the old days the announcement was made to the wider public by a reader on radio, but today that's replaced by the Internet and social media: As soon as the bulletin is fixed on the easel, officials will post the news on Twitter to millions of followers worldwide.
TO NANNY OR NOT
William and Kate have not made any public announcements about hiring a nanny to help them bring up their child. Many expect the couple to be more hands-on parents than earlier generations of royals, and some have speculated that because of the couple's close ties with Kate's parents, Michael and Carole Middleton will also have a big role in helping Kate with the baby.
Nannies have always been central to bringing up royal babies. Charles was famously close to his nannies, and William and Harry also enjoyed a bond with their former nanny Tiggy Legge-Bourke - who was so well known that she herself frequently appeared in the news.
A WELCOME WITH A BANG
Some things don't really change. A 62-gun salute from the Tower of London and a 41-gun salute from Green Park, near Buckingham Palace, will welcome the baby into the world with a bang, just as it did when previous royals were born. If the baby is born on a weekday, the salute will be mounted within six hours; if it's a weekend birth, the salute will wait until Monday, the Ministry of Defense says.