Britain's William and Kate might see themselves as modern parents, but they are under pressure to choose a name for their baby that is seen as fitting for a future king or queen.

The illustrious list of earlier monarchs includes names that are still popular among British parents, such as George, Edward and Victoria. But there are also plenty that have gone out of fashion, including Ethelred, Hardicanute and Athelstan.

The baby's birth will be officially announced on a golden easel at the gates of Buckingham Palace, along with confirmation of whether it is a boy or girl.

But it could be a while before the all-important name is announced.

When William was born in 1982, his name was not revealed for a week -- and when his father Prince Charles, the heir to the throne, was born in 1948, the suspense lasted an entire month.

The new father's full name is William Arthur Philip Louis -- Philip after his grandfather, Queen Elizabeth II's husband Prince Philip, and Louis after Philip's uncle Louis Mountbatten, the last viceroy of India, who was also Charles's mentor.

Charles's full name is Charles Philip Arthur George, while the queen's is Elizabeth Alexandra Mary.

Neither of these is quite the mouthful that was given to King Edward VIII, who reigned for only 10 months in 1936 before abdicating in order to marry the American divorcee Wallis Simpson.

In full, his parents named him Edward Albert Christian George Andrew Patrick David, the last four after the patron saints of England, Scotland, Ireland and Wales. At home he was called simply David.

British bookmakers have been doing a roaring trade in bets on the baby's name, with Alexandra emerging as the favourite girl's name, and George for a boy.

As well as being the current queen's middle name, Alexandra was the wife of king Edward VII, who ruled from 1901 to 1910, while the great queen Victoria's full name was Alexandrina Victoria.

There have been six king Georges including the current queen's father George VI, whose story was brought to life in the Oscar-winning 2010 film "The King's Speech."

As is the custom in many British families, William and Kate are expected to give a nod to close relatives when choosing a name for their baby.

William's mother Princess Diana died in 1997, and even if her name does not prove the top choice for a new princess it could be one of her middle names.

Kate's siblings James and Pippa, short for Philippa, could also be chosen as middle names, as could the names of her parents Michael and Carole.

Charles Kidd, editor of the Debrett's genealogical guide to the British aristocracy, predicts the couple will trawl through William's family tree for a name, settling on one that will not get their child bullied at the playground.

"As far as Christian names are concerned, we are not a nation that tires of tradition," he told The Times newspaper.

"For example, the sons of William the Conqueror had names that are as familiar and as popular today: Robert, Richard, William and Henry."

According to Kidd's research, the most popular boys' names in the monarchy between William the Conqueror's rise to the throne in 1066 and the death of queen Anne in 1714 were Henry, John, William, Edward and Richard.

For girls, the historical favourites, including middle names, are Mary, Margaret, Joan, Elizabeth and Eleanor.

More exotic boys' names include Humphrey, Baldwin, Eustach, Alfonso, Archibald, Falkland and Manners, while lesser-used girls' names were Blanche, Agatha, Adeliza, Berangaria and Ursula.

Monarchs are free to choose the name they take when they actually rise to the throne. The queen's father was called prince Albert before reigning as George VI.